Methods and apparatus for receiving and/or using reduced resolution images

ABSTRACT

Methods and apparatus for using selective resolution reduction on images to be transmitted and/or used by a playback device are described. Prior to transmission one or more images of an environment are captured. Based on image content, motion detection and/or user input a resolution reduction operation is selected and performed. The reduced resolution image is communicated to a playback device along with information indicating a UV map corresponding to the selected resolution allocation that should be used by the playback device for rendering the communicated image. By changing the resolution allocation used and which UV map is used by the playback device different resolution allocations can be made with respect to different portions of the environment while allowing the number of pixels in transmitted images to remain constant. The playback device renders the individual images with the UV map corresponding to the resolution allocation used to generate the individual images.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/672,236 filed Aug. 8, 2017 which is a continuation of U.S.patent application Ser. No. 15/046,327 filed Feb. 17, 2016 which claimsthe benefit of U.S. Provisional Application Ser. No. 62/117,427 filedFeb. 17, 2015, U.S. Provisional Application Ser. No. 62/262,374 filedDec. 2, 2015, and U.S. Provisional Application Ser. No. 62/296,065 filedFeb. 16, 2016 with each of the listed applications being herebyexpressly incorporated by reference in its entirety.

FIELD

The present invention relates to methods and apparatus for capturing,streaming and/or playback of content, e.g., content which can be used tosimulate an environment.

BACKGROUND

Display devices which are intended to provide an immersive experiencenormally allow a user to turn his head and experience a correspondingchange in the scene which is displayed. Head mounted displays sometimessupport 360 degree viewing in that a user can turn around while wearinga head mounted display with the scene being displayed changing as theuser's head position changes.

With such devices a user should be presented with a scene that wascaptured in front of a camera position when looking forward and a scenethat was captured behind the camera position when the user turnscompletely around. While a user may turn his head to the rear, at anygiven time a user's field of view is normally limited to 120 degrees orless due to the nature of a human's ability to perceive a limited fieldof view at any given time.

In order to support 360 degrees of view, a 360 degree scene may becaptured using multiple cameras with the images being combined togenerate the 360 degree scene which is to be made available for viewing.

It should be appreciated that a 360 degree view includes a lot moreimage data than a simple forward view which is normally captured,encoded for normal television and many other video applications where auser does not have the opportunity to change the viewing angle used todetermine the image to be displayed at a particular point in time.

Given transmission constraints, e.g., network data constraints,associated with content being streamed, it may not be possible to streamthe full 360 degree view in full high definition video to all customersseeking to receive and interact with the content. This is particularlythe case where the content is stereoscopic content including imagecontent intended to correspond to both left eye views and right eyeviews to allow for a 3D viewing effect.

In view of the above discussion it should be appreciated that there is aneed for methods and apparatus for supporting encoding and/or streamingof content in a manner which allows an individual user to be suppliedwith a wide viewing area, so that the playback device has image dataavailable should a user turn his/her head to view a different portion ofthe environment while satisfying data transmission constraints.

SUMMARY

Methods and apparatus for supporting delivery, e.g., streaming, of videoor other content corresponding to an environment are described. In someembodiments the images corresponding to the environment which arecommunicated to a playback device exceed the area a user can view at agiven time so that content is available in the event the user changeshis/her viewing angle by, for example, moving his/her head. By providingimages for an environmental area larger than that which can be viewed bya user at a given time the playback device has enough information toprovide images should the user's viewing angle change without theplayback device having to wait for new images or other contentcorresponding to a portion of the environment which the user was notpreviously viewing.

In at least some embodiments the environment is represented using a meshmodel. Images are captured and encoded into frames. At the playbackdevice the encoded images are decoded and applied to a surface of theenvironmental model, e.g., as a texture. The mapping of an image to thesurface of the environmental model is in accordance with a texture mapalso sometimes referred to as a UV map. Generally, but not necessarilyin all embodiments, a segment of a UV map corresponds to a segment ofthe 3D mesh model. In the playback device a UV map is applied to theimage and the segments of the image are then applied to thecorresponding segments of the 3D model as a texture. In this way a UVmap can be used to map a portion of a received image onto acorresponding portion of a model of an environment. To achieve a 3Deffect this process is used in some embodiments to map imagescorresponding to a left eye view onto the 3D model with the result beingdisplayed to a user's left eye. An image corresponding to a right eyeview is mapped onto the 3D model to generate an image which is displayedto the user's right eye. Differences between the left and right eyeviews in 3D embodiments result in a user perceiving images in 3D.

In the case of 3D images where data corresponding to left and right eyeimages is normally communicated, the amount of data required to support3D viewing can be considerable since data for two images instead of oneneeds to be communicated to allow for 3D viewing. Unfortunately,bandwidth constraints in many cases may make it difficult to transmittwo full resolution images particularly at the higher resolutionsviewers are beginning to expect.

A user's ability to detect the quality of an image decreases with regardto portions of an image the user is not directly looking at. In the caseof a scene of an environment a user is likely to be focused on viewingthe area of action in the environment, e.g., the portion of theenvironment where a ball is during a sporting game or where the actorsare on a stage or within the environment. The methods and apparatus ofthe present invention take advantage of this fact to selectivelyallocate resolution to the image being communicated. While reducing theresolution of images which are less likely to be viewed whilemaintaining the resolution of portions of images corresponding to anenvironment which are likely to be viewed, it is possible to makeefficient use of limited bandwidth available for streaming image data toa playback device.

In various embodiments images of an environment are captured andselective reduction of resolution is applied. The reduction inresolution may be, and sometimes is, applied to portions of an imageperceived to correspond to less important portions of an environment.While an environmental model may remain fixed, in various embodimentsthe resolution reduction applied to captured images may change as theportion of the environment of high importance changes. For example,while at the start of a soccer game the center field may be consideredthe important area of the environment since that is where the kickoffoccurs, as the ball moves to the left end of the field from the viewersperspective the left end may become more important than the otherportions of the field. As the ball moves to the right end of the fieldthe right end of the field may be more important from the viewersperspective than the left and center portions where the ball is notlocated.

In accordance with one embodiment, a resolution allocation is made basedon the relative importance of different portions of an environment at agiven time with more resolution being allocated to portions of imagescorresponding to areas of an environment perceived to be of highimportance than areas of low importance. The relative importance may bebased on motion detected in captured video providing the images beingcommunicated, from user input such as by tracking where users arelooking during the capture of images and/or through control of anoperator of the encoding and/or streaming system.

In some embodiments a set of different resolution allocations aresupported. Down-sampling or another resolution reduction technique isapplied to portions of an image the selected resolution allocationindicates are to be subject to resolution reduction while other portionsof the image may be left at full resolution or subject to a lesseramount of resolution reduction. A different texture map is used fordifferent resolution allocations. Thus, while the overall size and/ornumber of bits of an image communicated to a playback device may be, andsometimes is, the same for different resolution allocations, the texturemap (UV map) may be and often will be different for different resolutionallocations. In this way different UV maps in combination with selectiveresolution reduction can be used to allocate different amounts ofresolution to different portions of an image of an environment dependingon which portion of the environment is considered important at a givenpoint in time while the same environmental model is used despite thedifferent allocations of resolution.

Depending on the embodiment, a set of UV maps corresponding to a portionof the simulated environment may be communicated to the playback devicewith the streaming device then indicating which UV map is to be used fora communicated image or image pair. An image of an entire 360 degreeworld view including sky and ground images is communicated in a singleframe to a playback device in some embodiments. In other embodiments,images to be used as textures for different portions of an environmentare communicated as separate frames. For example, an image of the groundmay be sent separately, and not updated as frequently, as an image to beused for a 360 degree horizontal portion of the environment whileanother image may be sent for a sky view. The resolution allocationselection and indication of a corresponding UV map may be, and sometimesis, performed for each portion of the environment included in the streamas a separate image.

The UV maps, also referred to herein as texture maps and sometimes asimage maps, are normally communicated to the playback device before theyare required for rendering. They can be communicated in the contentstream with which they are to be used or sent separately. Oncecommunicated to a playback device, the UV maps can be, and sometimesare, stored. After a UV map is stored the streaming device can indentifythe map by communicating a map identifier in the content stream alongwith the image or images to which the UV map is applied.

Since the resolution allocation is made prior to encoding, the encodingdevice and/or streaming device normally associates in the image streamthe UV map and/or a map identifier with the communicated image orimages. In this way the playback device knows which UV map to use whenmapping a received image as part of a rendering operation.

Rendered images are displayed to a user with left eye images of an imagepair being displayed to a user's left eye and right eye images displayedto a user's right eye.

By using UV maps in combination with selective resolution reduction,different resolutions can be allocated to portions of an environment ina relatively easy to implement manner without requiring changes to bemade to the encoder being used to encode images which have been subjectto different resolution allocations and without requiring specialdecoding of images.

While the methods are well suited for 3D applications where left andright eye images are communicated to provide an stereoscopic image pair,the methods may be and sometimes are used for non-stereoscopicembodiments with selective resolution allocation and corresponding UVmaps being used in cases where a single image stream is communicated toa playback device, e.g., with the individual images being decoded andrendered onto the environmental map but with the same image beingdisplayed to both eyes of a user. Alternatively, the methods can be usedfor embodiments where a single stream of images is communicated to theplayback device and the playback device uses computational processing togenerate a pair of eye views from a single stream of received images,e.g., by receiving an image and generating a left eye image and adifferent right eye image from the single received image.

Numerous additional methods and embodiments are described in thedetailed description which follows.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an exemplary system implemented in accordance withsome embodiments of the invention which can be used to capture content,stream content, and output content to one or more users playback devicesin accordance with any of the embodiments described herein.

FIG. 2A illustrates an exemplary stereoscopic scene, e.g., a full 360degree stereoscopic scene which has not been partitioned.

FIG. 2B illustrates an exemplary stereoscopic scene which has beenpartitioned into 3 exemplary scenes in accordance with one exemplaryembodiment.

FIG. 2C illustrates an exemplary stereoscopic scene which has beenpartitioned into 4 scenes in accordance with one exemplary embodiment.

FIG. 3 illustrates an exemplary process of encoding an exemplary 360degree stereoscopic scene in accordance with one exemplary embodiment.

FIG. 4 illustrates an example showing how an input image portion isencoded using a variety of encoders to generate different encodedversions of the same input image portion.

FIG. 5 illustrates stored encoded portions of an input stereoscopicscene that has been partitioned into 3 portions.

FIG. 6 illustrates the combination of FIGS. 6A and 6B.

FIG. 6A illustrates a first part of a flowchart illustrating the stepsof an exemplary method of streaming content in accordance with anexemplary embodiment implemented using the system of FIG. 1 in whichselective resolution allocation and different UV maps are used atdifferent times.

FIG. 6B illustrates a second part of a flowchart illustrating the stepsof an exemplary method of streaming content in accordance with anexemplary embodiment implemented using the system of FIG. 1 in whichselective resolution allocation and different UV maps are used atdifferent times.

FIG. 7 illustrates an exemplary content delivery system with resolutionallocation selection, resolution reduction and encoding capability thatcan be used to encode and stream content, along with corresponding UVmaps, in accordance with the features of the invention.

FIG. 8 illustrates an exemplary content playback device that can be usedto receive, decode and display the content streamed by the system ofFIG. 7 and may use the UV maps shown and described with reference toFIG. 24 and/or various other figures to allow different UV maps to beused for images having different resolution allocations.

FIG. 9 illustrates the combination of FIGS. 9A and 9B.

FIG. 9A illustrates the first part of an exemplary method of operating acontent playback device in accordance with the present invention.

FIG. 9B illustrates the second part of an exemplary method of operatinga content playback device in accordance with the present invention.

FIG. 10 illustrates an exemplary method of communicating information tobe used to represent an environment in accordance with the presentinvention.

FIG. 11 illustrates an exemplary image capture and content streamingmethod in accordance with an exemplary embodiment in which differentresolution allocations can be used for images corresponding to the sameenvironmental portion at different times.

FIG. 12 illustrates a method of operating a playback device or system,e.g., a rendering device, which can be used in the system of FIG. 1, toreceive and render images using UV maps and an environmental model inaccordance with one exemplary embodiment.

FIG. 13 illustrates a camera rig including multiple camera pairs forcapturing left and right eye images corresponding to different sectorsof a 360 degree field of view along with a camera or cameras directedtowards the sky to capture a sky view.

FIG. 14 shows how 5 different environmental mesh maps, corresponding todifferent camera views, can be combined to create a complete sphericalview/environment onto which captured images can be projected, e.g., ontothe inner surface, as part of a playback operation.

FIG. 15 shows the full assembly of 5 meshes shown in FIG. 14 to create aspherical simulated environment which can be viewed from a user as ifhe/she were located at the center of the environment, e.g., sphere.

FIG. 16 shows a left eye view image and a right eye view image capturedby left and right eye cameras, with fisheye lenses, corresponding to asector of the camera rig shown in FIG. 13.

FIG. 17A shows an exemplary mesh model of an environment in accordancewith the invention.

FIG. 17B shows a UV map which can be used to map portions of a 2D imageonto surfaces of the mesh model shown in FIG. 17A.

FIG. 18 shows how captured left and right eye view images of FIG. 16 mayappear after cropping prior to encoding and transmission to one or moreplayback devices.

FIG. 19 shows an environmental mesh model corresponding to one sector ofthe camera rig with one of the images shown in FIG. 18 applied, e.g.,projected, onto the environmental mesh.

FIG. 20 shows application of images captured by cameras corresponding toeach of the sectors as well as the sky and ground cameras of the camerarig can be combined and projected onto the modeled environment tosimulate a complete 360 environment in the form of a sphere.

FIG. 21 shows how selective resolution can be used with regard to aframe which maps to an environmental grid with different resolutionsbeing used for different portions of the image to be mapped to theenvironmental model, e.g., with smaller portions of the transmittedimage being mapped to corresponding portions of the sky and ground meshsegments than the segments of the middle portion of the environmentresulting in lower resolution being allocated to the top and bottomportions of the environment than the middle portion of the environment.

FIG. 22 shows a first captured image of a first portion of anenvironment, a first resolution adjusted image generated using a firstresolution allocation from the first captured image, and a first UV mapcorresponding to the first resolution allocation.

FIG. 23 shows a second captured image of the first portion of theenvironment, a second resolution adjusted image generated using a secondresolution allocation from the second captured image, and a second UVmap corresponding to the second resolution allocation.

FIG. 24 shows a third captured image of the first portion of theenvironment, a third resolution adjusted image generated using a thirdresolution allocation from the third captured image, and a third UV mapcorresponding to the second resolution allocation.

FIG. 25 illustrates the combination of FIGS. 25A and 25B.

FIG. 25A shows a first part of a method of operating a contentprocessing and delivery system in accordance with an exemplaryembodiment.

FIG. 25B shows a second part of a method of operating a contentprocessing and delivery system in accordance with an exemplaryembodiment.

FIG. 26 illustrates an exemplary embodiment of a method of playing backcontent in accordance with the invention.

FIG. 27 illustrates an example of how a playback device, such as theplayback device or devices shown in any of the other figures, canperform image rendering using a UV map corresponding to the resolutionallocation that was used to generate the image to be rendered.

FIG. 28 illustrates an example of how a playback device, such as theplayback device or devices shown in any of the other figures, canperform image rendering using a UV map corresponding to the resolutionallocation that was used to generate the image to be rendered.

FIG. 29 illustrates an example of how a playback device, such as theplayback device or devices shown in any of the other figures, canperform image rendering using a UV map corresponding to the resolutionallocation that was used to generate the image to be rendered.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary system 100 implemented in accordancewith some embodiments of the invention. The system 100 supports contentdelivery, e.g., imaging content delivery, to one or more customerdevices, e.g., playback devices/content players, located at customerpremises. The system 100 includes the exemplary image capturing device102, a content delivery system 104, a communications network 105, and aplurality of customer premises 106, . . . , 110. The image capturingdevice 102 supports capturing of stereoscopic imagery. The imagecapturing device 102 captures and processes imaging content inaccordance with the features of the invention. The communicationsnetwork 105 may be, e.g., a hybrid fiber-coaxial (HFC) network,satellite network, and/or internet.

The content delivery system 104 includes an image processing,calibration and encoding apparatus 112 and a content delivery device,e.g. a streaming server 114. The image processing, calibration andencoding apparatus 112 is responsible for performing a variety offunctions including camera calibration based on one or more targetimages and/or grid patterns captured during a camera calibrationprocess. Content delivery device 114 may be implemented as a serverwith, as will be discussed below, the delivery device responding torequests for content with image calibration information, optionalenvironment information, and one or more images captured by the camerarig 102 which can be used in simulating a 3D environment. Streaming ofimages and/or content may be and sometimes is a function of feedbackinformation such as viewer head position and/or user selection of aposition at the event corresponding to a camera 102 which is to be thesource of the images. For example, a user may select or switch betweenimages from a camera rig positioned at center line to a camera rigpositioned at the field goal with the simulated 3D environment andstreamed images being changed to those corresponding to the userselected camera rig. Thus it should be appreciated that while a singlecamera rig 102 is shown in FIG. 1 multiple camera rigs may be present inthe system and located at different physical locations at a sporting orother event with the user being able to switch between the differentpositions and with the user selections being communicated from theplayback device 122 to the content server 114. While separate devices112, 114 are shown in the image processing and content delivery system104, it should be appreciated that the system may be implemented as asingle device including separate hardware for performing the variousfunctions or with different functions being controlled by differentsoftware or hardware modules but being implemented in or on a singleprocessor.

Encoding apparatus 112 may, and in some embodiments does, include one ora plurality of encoders for encoding image data in accordance with theinvention. The encoders may be used in parallel to encode differentportions of a scene and/or to encode a given portion of a scene togenerate encoded versions which have different data rates. Usingmultiple encoders in parallel can be particularly useful when real timeor near real time streaming is to be supported.

The content streaming device 114 is configured to stream, e.g.,transmit, encoded content for delivering the encoded image content toone or more customer devices, e.g., over the communications network 105.Via the network 105, the content delivery system 104 can send and/orexchange information with the devices located at the customer premises106, 110 as represented in the figure by the link 120 traversing thecommunications network 105.

While the encoding apparatus 112 and content delivery server are shownas separate physical devices in the FIG. 1 example, in some embodimentsthey are implemented as a single device which encodes and streamscontent. The encoding process may be a 3D, e.g., stereoscopic, imageencoding process where information corresponding to left and right eyeviews of a scene portion are encoded and included in the encoded imagedata so that 3D image viewing can be supported. The particular encodingmethod used is not critical to the present application and a wide rangeof encoders may be used as or to implement the encoding apparatus 112.

Each customer premise 106, 110 may include a plurality ofdevices/players, e.g., decoding apparatus to decode and playback/displaythe image content streamed by the content streaming device 114. Customerpremise 1 106 includes a decoding apparatus/playback device 122 coupledto a display device 124 while customer premise N 110 includes a decodingapparatus/playback device 126 coupled to a display device 128. In someembodiments the display devices 124, 128 are head mounted stereoscopicdisplay devices.

In various embodiments decoding apparatus 122, 126 present the imagingcontent on the corresponding display devices 124, 128. The decodingapparatus/players 122, 126 may be devices which are capable of decodingthe imaging content received from the content delivery system 104,generate imaging content using the decoded content and rendering theimaging content, e.g., 3D image content, on the display devices 124,128. Any of the decoding apparatus/playback devices 122, 126 may be usedas the decoding apparatus/playback device 800 shown in FIG. 8. Asystem/playback device such as the one illustrated in FIG. 8 can be usedas any of the decoding apparatus/playback devices 122, 126.

FIG. 2A illustrates an exemplary stereoscopic scene 200, e.g., a full360 degree stereoscopic scene which has not been partitioned. Thestereoscopic scene may be and normally is the result of combining imagedata captured from multiple cameras, e.g., video cameras, often mountedon a single video capture platform or camera mount.

FIG. 2B illustrates a partitioned version 250 of the exemplarystereoscopic scene 200 where the scene has been partitioned into 3 (N=3)exemplary portions, e.g., a front 180 degree portion, a left rear 90degree portion and a right rear 90 degree portion in accordance with oneexemplary embodiment.

FIG. 2C illustrates another portioned version 280 of the exemplarystereoscopic scene 200 which has been partitioned into 4 (N=4) portionsin accordance with one exemplary embodiment.

While FIGS. 2B and 2C show two exemplary partitions, it should beappreciated that other partitions are possible. For example the scene200 may be partitioned into twelve (n=12) 30 degree portions. In onesuch embodiment, rather than individually encoding each partition,multiple partitions are grouped together and encoded as a group.Different groups of partitions may be encoded and streamed to the userwith the size of each group being the same in terms of total degrees ofscene but corresponding to a different portion of an image which may bestreamed depending on the user's head position, e.g., viewing angle asmeasured on the scale of 0 to 360 degrees.

FIG. 3 illustrates an exemplary process of encoding an exemplary 360degree stereoscopic scene in accordance with one exemplary embodiment.The input to the method 300 shown in FIG. 3 includes 360 degreestereoscopic image data 302 captured by, e.g., a plurality of camerasarranged to capture a 360 degree view of a scene. The stereoscopic imagedata 302, e.g., stereoscopic video, may be in any of a variety of knownformats and includes, in most embodiments, left and right eye image dataused to allow for a 3D experience. While the methods are particularlywell suited for stereoscopic video, the techniques and methods describedherein can also be applied to 2D images, e.g., of a 360 degree or smallscene area.

In step 304 the scene data 302 is partitioned into data corresponding todifferent scene areas, e.g., N scene areas corresponding to differentviewing directions. For example, in one embodiment such as the one shownin FIG. 2B the 360 degree scene area is portioned into three partitionsa left rear portion corresponding to a 90 degree portion, a front 180degree portion and a right rear 90 degree portion. The differentportions may have been captured by different cameras but this is notnecessary and in fact the 360 degree scene may be constructed from datacaptured from multiple cameras before being dividing into the N sceneareas as shown in FIGS. 2B and 2C.

In step 306 the data corresponding to the different scene portions isencoded in accordance with the invention. In some embodiments each sceneportion is independently encoded by multiple encoders to supportmultiple possible bit rate streams for each portion. In step 308 theencoded scene portions are stored, e.g., in the content delivery system104, for streaming to the customer playback devices.

FIG. 4 is a drawing 400 illustrating an example showing how an inputimage portion, e.g., a 180 degree front portion of a scene, is encodedusing a variety of encoders to generate different encoded versions ofthe same input image portion.

As shown in drawing 400, an input scene portion 402 e.g., a 180 degreefront portion of a scene, is supplied to a plurality of encoders forencoding. In the example there are K different encoders which encodeinput data with different resolutions and using different encodingtechniques to generate encoded data to support different data ratestreams of image content. The plurality of K encoders include a highdefinition (HD) encoder 1 404, a standard definition (SD) encoder 2 406,a reduced frame rate SD encoder 3 408, . . . , and a high compressionreduced frame rate SD encoder K 410.

The HD encoder 1 404 is configured to perform full high definition (HD)encoding to produce high bit rate HD encoded image 412. The SD encoder 2406 is configured to perform low resolution standard definition encodingto produce a SD encoded version 2 414 of the input image. The reducedframe rate SD encoder 3 408 is configured to perform reduced frame ratelow resolution SD encoding to produce a reduced rate SD encoded version3 416 of the input image. The reduced frame rate may be, e.g., half ofthe frame rate used by the SD encoder 2 406 for encoding. The highcompression reduced frame rate SD encoder K 410 is configured to performreduced frame rate low resolution SD encoding with high compression toproduce a highly compressed reduced rate SD encoded version K 420 of theinput image.

Thus it should be appreciated that control of spatial and/or temporalresolution can be used to produce data streams of different data ratesand control of other encoder settings such as the level of datacompression may also be used alone or in addition to control of spatialand/or temporal resolution to produce data streams corresponding to ascene portion with one or more desired data rates.

FIG. 5 illustrates stored encoded portions 500 of an input stereoscopicscene that has been partitioned into 3 exemplary portions. The storedencoded portions may be stored in the content delivery system 104, e.g.,as data/information in the memory. The stored encoded portions 500 ofthe stereoscopic scene includes 3 different sets of encoded portions,with each portion corresponding to a different scene area and each setincluding a plurality of different encoded versions of the correspondingscene portion. Each encoded version is a version of encoded video dataand thus represents multiple frames which have been coded. It should beappreciated that each encoded version 510, 512, 516 is video thatcorresponds to multiple periods of time and that when streaming, theportion, e.g., frames, corresponding to the period of time being playedback will be used for transmission purposes.

As illustrated and discussed above with regard to FIG. 4, each sceneportion, e.g., front, rear scene portions, may be encoded using aplurality of different encoders to produce K different versions of thesame scene portion. The outputs of each encoder corresponding to a giveninput scene are grouped together as a set and stored. The first set ofencoded scene portions 502 corresponds to the front 180 degree sceneportion, and includes encoded version 1 510 of the front 180 degreescene, encoded version 2 512, . . . , and encoded version K 516. Thesecond set of encoded scene portions 504 corresponds to the sceneportion 2, e.g., 90 degree left rear scene portion, and includes encodedversion 1 520 of the 90 degree left rear scene portion, encoded version2 522, . . . , and encoded version K 526 of the 90 degree left rearscene portion. Similarly the third set of encoded scene portions 506corresponds to the scene portion 3, e.g., 90 degree right rear sceneportion, and includes encoded version 1 530 of the 90 degree right rearscene portion, encoded version 2 532, . . . , and encoded version K 536of the 90 degree right rear scene portion.

The various different stored encoded portions of the 360 degree scenecan be used to generate various different bit rate streams for sendingto the customer playback devices.

The content delivery system 104 can support a large number of concurrentusers since, the encoding process allows the N portions of a scene to betransmitted and processed differently to different users without havingto encode the content separately for each individual user. Thus, while anumber of parallel encoders may be used to support real time encoding toallow for real or near real time streaming of sports or other events,the number of encoders used tends to be far less than the number ofplayback devices to which the content is streamed.

While the portions of content are described as portions corresponding toa 360 degree view it should be appreciated that the scenes may, and insome embodiments do, represent a flattened version of a space which alsohas a vertical dimension. The playback device is able to map the sceneportions using a model of the 3D environment, e.g., space, and adjustfor vertical viewing positions. Thus, the 360 degrees which arediscussed in the present application refer to the head position relativeto the horizontal as if a user changed his viewing angle left or rightwhile holding his gaze level.

FIG. 6 which comprises FIGS. 6A and 6B is a flowchart 600 illustratingthe steps of an exemplary method of providing image content, inaccordance with an exemplary embodiment. FIG. 6A illustrates the firstpart of the flowchart 600. FIG. 6B illustrates the second part offlowchart 600. The method of flowchart 600 is implemented in someembodiments using the capturing system shown in FIG. 1.

The method 600 commences in start step 602 shown in FIG. 6A. Operationproceeds from step 602 to step 604. In step 604, a captured image isreceived. Operation proceeds from step 604 to step 606.

In step 606, the resolution allocation to be used is selected. Theselection may be made for example based on motion. Operation proceedsfrom step 606 to decision step 608. In decision step 608, if adetermination is made that the selected resolution is different from theprevious resolution allocation then operation proceeds to step 610.Otherwise operation proceeds to step 612.

In step 610 new downsampling and/or filtering information correspondingto the selected resolution allocation used to control resolutionreduction is loaded. Operation proceeds from step 610 to step 612.

In step 612, a resolution reduction operation is performed on thereceived captured image based on the determined resolution allocation tobe used. The resolution reduction operation outputs a reduced resolutionimage 614 with at least some different image portions having differentresolutions. Operation proceeds to step 616.

In step 616, the reduced resolution image is encoded using an encoderwhich supports compression, e.g., entropy encoding, run length encoding,motion vectors and/or other encoding techniques. Operation proceeds fromstep 616 to step 618.

In step 618, a UV map corresponding to the resolution allocation to beused for rendering the image subjected to determined resolutionallocation, e.g., down sampling, is indicated. By specifying the UV mapcorresponding to the applied resolution allocation and/or by providing aUV map corresponding to the applied resolution allocation the playbackdevice is provided with information which allows the communicated imageto be applied to the 3D model of the environment taking intoconsideration which portions of the transmitted image were downsampledprior to being communicated to the playback device. Operation proceedsfrom step 618 to decision step 622 shown on FIG. 6B via connection nodeA 620.

In decision step 622 a determination is made as to whether the UV mapcorresponding to the applied resolution allocation has been communicatedto the playback device. If the determination is that the UV mapcorresponding to the applied resolution allocation has not beencommunicated to the playback device then operation proceeds to step 624.If the determination is that the UV map corresponding to the appliedresolution allocation has been communicated to the playback device thenoperation proceeds to step 626.

In step 624, the UV map corresponding to the applied resolutionallocation is communicated to the playback device. Operation proceedsfrom step 624 to step 626.

In step 626, information indicating the UV map to use is communicated tothe playback device. Operation proceeds from step 626 to step 628. Instep 628, the encoded image is communicated to the playback device. Thismethod may be executed with respect to each received captured image.

FIG. 7 illustrates an exemplary content delivery system 700 withencoding capability that can be used to encode and stream content inaccordance with the features of the invention.

The system may be used to perform encoding, storage, and transmissionand/or content output in accordance with the features of the invention.In some embodiments the system 700 or the elements therein perform theoperation corresponding to the process illustrated in FIG. 6. Thecontent delivery system 700 may be used as the system 104 of FIG. 1.While the system shown in FIG. 7 is used for encoding, processing andstreaming of content, it should be appreciated that the system 700 mayalso include the ability to decode and display processed and/or encodedimage data, e.g., to an operator.

The system 700 includes a display 702, input device 704, input/output(I/O) interface 706, a processor 708, network interface 710 and a memory712. The various components of the system 700 are coupled together viabus 709 which allows for data to be communicated between the componentsof the system 700.

The memory 712 includes various modules, e.g., routines, which whenexecuted by the processor 708 control the system 700 to implement thepartitioning, encoding, storage, and streaming/transmission and/oroutput operations in accordance with the invention.

The memory 712 includes various modules, e.g., routines, which whenexecuted by the processor 707 control the computer system 700 toimplement the immersive stereoscopic video acquisition, encoding,storage, and transmission and/or output methods in accordance with theinvention. The memory 712 includes control routines 714, a partitioningmodule 716, encoder(s) 718, a streaming controller 720, received inputimages 732, e.g., 360 degree stereoscopic video of a scene, encodedscene portions 734, and timing information 736. In some embodiments themodules are, implemented as software modules. In other embodiments themodules are implemented in hardware, e.g., as individual circuits witheach module being implemented as a circuit for performing the functionto which the module corresponds. In still other embodiments the modulesare implemented using a combination of software and hardware.

The control routines 714 include device control routines andcommunications routines to control the operation of the system 700. Thepartitioning module 716 is configured to partition a receivedstereoscopic 360 degree version of a scene into N scene portions inaccordance with the features of the invention.

The encoder(s) 718 may, and in some embodiments do, include a pluralityof encoders configured to encode received image content, e.g., 360degree version of a scene and/or one or more scene portions inaccordance with the features of the invention. In some embodimentsencoder(s) include multiple encoders with each encoder being configuredto encode a stereoscopic scene and/or partitioned scene portions tosupport a given bit rate stream. Thus in some embodiments each sceneportion can be encoded using multiple encoders to support multipledifferent bit rate streams for each scene. An output of the encoder(s)718 is the encoded scene portions 734 which are stored in the memory forstreaming to customer devices, e.g., playback devices. The encodedcontent can be streamed to one or multiple different devices via thenetwork interface 710.

UV maps 740 are stored in memory 712 of the content delivery system 700.The UV maps 740 correspond to different resolution allocations and/orareas of the environment. For example, the first UV map 1 742corresponds to a first resolution allocation, the second UV map 2 744corresponds to a second resolution allocation, and the third UV map 746corresponds to a third resolution allocation. UV maps with differentresolution allocations can correspond to the same area of anenvironment. Different UV maps corresponding to other areas of theenvironment can be stored in the memory 712. Multiple UV maps maycorrespond to the environmental model. The mesh model of the environmentwhere the received images were captured is stored in memory 712 of thecontent delivery system 700, e.g., 3D environmental mesh model 738.Multiple mesh models may be stored in the memory 712.

The streaming controller 720 is configured to control streaming ofencoded content for delivering the encoded image content to one or morecustomer devices, e.g., over the communications network 105. In variousembodiments various steps of the flowchart 600 are implemented by theelements of the streaming controller 720. The streaming controller 720includes a request processing module 722, a data rate determinationmodule 724, a current head position determination module 726, aselection module 728 and a streaming control module 730. The requestprocessing module 722 is configured to process a received request forimaging content from a customer playback device. The request for contentis received in various embodiments via a receiver 713 in the networkinterface 710. In some embodiments the request for content includesinformation indicating the identity of requesting playback device. Insome embodiments the request for content may include data ratessupported by the customer playback device, a current head position ofthe user, e.g., position of the head mounted display. The requestprocessing module 722 processes the received request and providesretrieved information to other elements of the streaming controller 720to take further actions. While the request for content may include datarate information and current head position information, in variousembodiments the data rate supported by the playback device can bedetermined from network tests and other network information exchangebetween the system 700 and the playback device.

The data rate determination module 724 is configured to determine theavailable data rates that can be used to stream imaging content tocustomer devices, e.g., since multiple encoded scene portions aresupported the content delivery system 700 can support streaming contentat multiple data rates to the customer device. The data ratedetermination module 724 is further configured to determine the datarate supported by a playback device requesting content from system 700.In some embodiments the data rate determination module 724 is configuredto determine data rates for delivery of image content based on networkmeasurements.

The current head position determination module 726 is configured todetermine a current viewing angle and/or a current head position of theuser, e.g., position of the head mounted display, from informationreceived from the playback device. In some embodiments the playbackdevice periodically sends current head position information to thesystem 700 where the current head position determination module 726receives and processes the information to determine the current viewingangle and/or a current head position.

The selection module 728 is configured to determine which portions of a360 degree scene to stream to a playback device based on the currentviewing angle/head position information of the user. The selectionmodule 728 is further configured to select the encoded versions of thedetermined scene portions based on the available data rates to supportstreaming of content.

The streaming control module 730 is configured to control streaming ofimage content, e.g., multiple portions of a 360 degree stereoscopicscene, at various supported data rates in accordance with the featuresof the invention. In some embodiments the streaming control module 730is configured to control the streaming of N portions of a 360 degreestereoscopic scene to the playback device requesting content toinitialize scene memory in the playback device. In various embodimentsthe streaming control module 730 is configured to send the selectedencoded versions of the determined scene portions periodically, e.g., ata determined rate. In some embodiments the streaming control module 730is further configured to send 360 degree scene updates to the playbackdevice in accordance with a time interval, e.g., once every minute. Insome embodiments sending 360 degree scene update includes sending Nscene portions or N-X scene portions of the full 360 degree stereoscopicscene, where N is the total number of portions into which the full 360degree stereoscopic scene has been partitioned and X represents theselected scene portions recently sent to the playback device. In someembodiments the streaming control module 730 waits for a predeterminedtime after initially sending N scene portions for initialization beforesending the 360 degree scene update. In some embodiments the timinginformation to control sending of the 360 degree scene update isincluded in the timing information 736. In some embodiments thestreaming control module 730 is further configured identify sceneportions which have not been transmitted to the playback device during arefresh interval; and transmit an updated version of the identifiedscene portions which were not transmitted to the playback device duringthe refresh interval.

In various embodiments the streaming control module 730 is configured tocommunicate at least a sufficient number of the N portions to theplayback device on a periodic basis to allow the playback device tofully refresh a 360 degree version of said scene at least once duringeach refresh period.

FIG. 8 illustrates a computer system/playback device 800 implemented inaccordance with the present invention which can be used to receive,decode, store and display imaging content received from a contentdelivery system such as the one shown in FIGS. 1 and 7. The playbackdevice may be used with a 3D head mounted display such as the OCULUSRIFT™ VR (virtual reality) headset which may be the head mounted display805. The device 800 includes the ability to decode the received encodedimage data and generate 3D image content for display to the customer.The playback device in some embodiments is located at a customer premiselocation such as a home or office but may be located at an image capturesite as well. The device 800 can perform signal reception, decoding,display and/or other operations in accordance with the invention.

The device 800 includes a display 802, a display device interface 803,input device 804, a decoder 864, input/output (I/O) interface 806, aprocessor 808, network interface 810 and a memory 812. The variouscomponents of the playback device 800 are coupled together via bus 809which allows for data to be communicated between the components of thesystem 800. While in some embodiments display 802 is included as anoptional element as illustrated using the dashed box, in someembodiments an external display device 805, e.g., a head mountedstereoscopic display device, can be coupled to the playback device viathe display device interface 803. In some embodiments, the networkinterface 810 includes a receiver 860 and a transmitter 862.

The memory 812 includes various modules, e.g., routines, which whenexecuted by the processor 808 control the playback device 800 to performdecoding and output operations in accordance with the invention. Thememory 812 includes control routines 814, a request for contentgeneration module 816, a head position and/or viewing angledetermination module 818, a decoder module 820, a stereoscopic imagerendering module 822 also referred to as a 3D image generation module,and data/information including received encoded image content 824,decoded image content 826, a 360 degree decoded scene buffer 828, andgenerated stereoscopic content 830.

The control routines 814 include device control routines andcommunications routines to control the operation of the device 800. Therequest generation module 816 is configured to generate a request forcontent to send to a content delivery system for providing content. Therequest for content is sent in various embodiments via the networkinterface 810. The head position and/or viewing angle determinationmodule 818 is configured to determine a current viewing angle and/or acurrent head position of the user, e.g., position of the head mounteddisplay, and report the determined position and/or viewing angleinformation to the content delivery system 700. In some embodiments theplayback device 800 periodically sends current head position informationto the system 700.

The decoder module 820 is configured to decode encoded image content 824received from the content delivery system 700 to produce decoded imagedata 826. The decoded image data 826 may include decoded stereoscopicscene and/or decoded scene portions.

The 3D image rendering module 822 generates 3D images in accordance withthe features of the invention, e.g., using the decoded image content826, for display to the user on the display 802 and/or the displaydevice 805. The generated stereoscopic image content 830 is the outputof the 3D image generation module 822. Thus the rendering module 822renders the 3D image content 830 to the display. In some embodiments thedisplay device 805 may be a 3D display such as an oculus rift. Theoperator of the playback device 800 may control one or more parametersvia input device 804 and/or select operations to be performed, e.g.,select to display 3D scene.

FIG. 8 illustrates an exemplary content playback device that can be usedto receive, decode and display the content streamed by the system ofFIG. 7. The system 800 includes a display interface 803 coupled to ahead mounted stereoscopic display 805, an input device 804, an optionaldisplay 802 and I/O interface. The interface 802 coupled the variousinput/output elements 803, 802, 804 to the bus 809 which in turn iscoupled to processor 808, network interface 810 and memory 812. Thenetwork interface 810 allows the playback device to receive content fromthe streaming device 114 and/or communicate information such as viewhead position and/or position (camera rig) selection indicatingselection of particular viewing position at an event. The memory 812includes various data and modules as shown in FIG. 8. When executed thedecoder module 820 causes received images to be decoded while 3D imagerendering module 822 causes further processing of the images inaccordance with the present invention and optionally stitching of imagestogether as part of the presentation process.

FIG. 9 which comprises a first part FIG. 9A and a second part FIG. 9Billustrates the steps 900 of a method of operating a content playbackdevice. In accordance with the method 900 different UV maps may be usedat different times for mapping a portion of one or more received imagesto an environmental model, e.g., a mesh model, of an environment. As aresult of using different UV maps, while the number of pixels in areceived image, e.g., encoded frame, may remain the same, the mapping ofpixels of a received image to a segment of the environmental model maychange. For example, using a first UV map may result in a first numberof pixels in a received image mapping to a first portion of anenvironmental model while use of a second different UV map may result ina different number of pixels in a received image mapping to the sameportion of the environmental model. The system generating andtransmitting the images also in some embodiments communicates the UVmaps and/or indicates to the playback device which UV map is to be usedwhen mapping an image or set of images to the environmental model. Thusby changing the UV map to be used the encoding and transmission devicecan change the amount of data and/or resolution associated with aparticular portion of the environmental model. Since the renderinginvolves stretching or otherwise conforming the indicated portion of animage to the corresponding segment of the 3D environmental model theimage content will be scaled and/or otherwise modified as needed as partof the rendering process to cover the segment of the 3D model to whichit applies. Consider for example if a first UV map maps one pixel to afirst segment of the environmental model and a second UV map maps twopixels to the first segment of the environmental model, the resolutionof the displayed first segment will be higher when the second UV map isused than when the first UV map is used for image rendering. While theUV map may be changed from image to image or from group of images togroup of images thereby allowing the server generating and sending theimages and UV map information to the playback device to dynamicallyalter the allocation of data and/or resolution within a portion of theenvironment, e.g., front portion, based on the scene areas considered ofparticular interest, e.g., scene areas where the actors, players,performers are in the environment or where movement is in theenvironment, the data rate used for transmitting images can be heldrelatively constant since the number of pixels in the images can remainthe same with the UV map controlling the allocation of pixels toportions of the environment. Thus the methods allow for the imageencoding technique to remain the same at least in some embodiments withthe captured image or images being downsampled differently prior toencoding depending on the location of the scene portions considered ofparticular interest within a captured image and based on knowledge ofwhich UV map will be used to apply the image, e.g., as a texture, to oneor more segments of an environmental module. While the UV map may bechanged on a per frame or image basis from one image or frame to thenext, in some embodiments the change in UV maps is constrained to occuron I-frame or group of picture boundaries with a UV map being used formultiple frames within a group of pictures or between I-frames. Whilesuch a UV map transition constraint is used in some embodiments, it isnot necessary or critical to the invention and some embodiments allowthe UV map to be changed on a per frame basis.

The steps of the exemplary method 900 will now be discussed in detail.The method 900 starts in step 902, e.g., with a content playback devicebeing powered on. The playback device may be, e.g., a game systemconnected to a head mounted display or TV or as is the case in variousembodiments a cell phone mounted in a head mount with a touch pad orother control and one or more lenses for allowing a user to view leftand right eye images on different portions of a cell phone screen whichis used as a display device. The method 900 may be implemented by any ofthe content playback devices described in the present application.

In step 903, e.g., in response to user input indicating user selectionof content to be played to a user, the content playback device transmitsa request for content in step 903. In some embodiments this request iscommunicated to a content server or content provider system, e.g., adevice which receives, processes and encodes images of an environmentand supplies them to the playback device along with UV maps and/orinformation about which UV map to be used at a given time. The servermay also provide an environmental model or a default model may be used.

In step 904 a model of an environment, e.g., a 3D mesh model isreceived, e.g., from the content server. The model may be and sometimesis a model of an environment where an event such as a play or sportingevent is ongoing. The model may be a complete 360 degree model of theenvironment or a model of the portion of the environment to which imagecontent is to be mapped, e.g., a front portion of the environment. Asshould be appreciated the features relating to using different UV mapsto map images to a portion of the environment may be used for a full 360degree environment, a portion of an environment, with stereo imagesand/or with non-stereoscopic images, e.g., panoramic images where thesame image is displayed to both left and right eyes of a viewer.

Operation proceeds from step 904 to step 906 in which model of theenvironment received in step 903 is stored for future use, e.g., inrendering and displaying images mapped onto the model in accordance withone of the UV maps, e.g., texture maps, which are received in step 908.The texture maps may be and sometimes are received from the same serverwhich provides the environmental model. The UV map indicates how a 2dimage should be segmented with the segments then being applied tocorresponding segments of the environmental model, e.g., as a texture ortextures.

While an initial texture, e.g., initial UV map, may be received in step908 in some embodiments a set of maps are received and stored with thedifferent UV maps indicating different mappings between an image and aportion of the environmental model. Each map may be identified by atexture map identifier. During streaming of content the content serverproviding the images can indicate which texture map to use with whichset of images. In other embodiments a new texture map may be streamedwith or before the images to which the new texture map is to be applied.Storing of a set of texture maps in the playback device can provideefficient transmission since the maps can be reused without transmittingthe UV/texture maps multiple times to the playback device.

In step 910 the received set of texture maps is stored for future use.With the texture maps having been stored, operation proceeds to step 914in which image content is received. In step 904 in addition to imagecontent an indicator identifying the texture map to be used to map thereceived image onto the model of the environment is received or thetexture map to be used is received. When an indicator is received itidentify the texture map in the stored set of texture maps which is tobe used. An indicated texture map may remain in effect until a newtexture map is specified and/or provided. Thus a single texture map maybe used for a sequence of images, e.g., a group of pictures. The texturemap may be changed by the sever when, e.g., motion is detectedindicating a different area of the environment is an area of higherpriority than an area to which high resolution was previously allocated.Thus as actors move or players on a field move, resolution allocationcan be changed and the UV map corresponding to the current resolutionallocation may be used in place of a previous UV map corresponding to adifferent resolution allocation.

Step 914 includes, in some embodiments steps 916, 918, 920, 926 and 928.

In step 916 a first encoded image is received. In step 918 which isoptional, a second encoded image is received.

In step 920 which is an alternative to steps 916, 918 an encoded frameincluding one or both images is received. The second encoded image maybe a second image of a stereoscopic image pair with the first and secondimages being left and right eye images to be displayed to a user of theplayback device. For example odd lines of a frame may provide the firstimage and even lines of the encoded frame may provide the second encodedimage. Alternatively a top half of an encoded frame may provide thefirst image and the bottom half the second image. Other ways ofincluding the first and second images in a single frame are alsopossible.

In step 914, in addition to receiving image content which can be mappedto the environmental model, in step 926 a first indicator indicatingwhich of a plurality of texture maps corresponding to differentresolution allocation is to be used with the received first and/orsecond encoded images is also received. If a new texture map indicatoris not received in step 914, and a new texture map is not received, theplayback device will continue to use the last UV map which was beingused. Rather than receive a texture map indicator, a new texture map maybe received in step 928 which is to be used in rendering the receivedimages.

With images received, e.g., in encoded form, operation proceeds fromstep 914 to step 930 In step 930 the received image or images aredecoded. For example in step 932 the first encoded image is decoded torecover a first image. In step 934 the second encoded image is decodedto recover a second image. As discussed above, the first and secondimages may be left and right eye views. In embodiments where the firstand second images are included in a single encoded frame decoding of thereceived frame and separation of the left and second images may be usedin step 930 to produce left and right eye images which may be andsometimes are applied separately to the environmental map to generateseparate, potentially different, left and right eye views.

In some embodiments the images communicate a complete 360 degreeenvironment or panoramic view. In other embodiments the first and secondimages may correspond to a portion of the environment, e.g., a frontportion or a 360 degree middle panoramic portion but not the sky andground. In step 936 other images which are sent with the encoded firstand second image or in a separate stream may be decoded to obtaintextures for portions of the environment which are not provided by thefirst and/or second images. In some embodiments in step 936 a sky orground image is obtained by decoding a received encoded image or frame.

With the decoding of images that were transmitted to the playback devicehaving been completed in step 930 operation proceeds to step 938 inwhich image content is rendered using the received, e.g., decoded imageor images, the UV map which was to be used in rendering the receivedimages, and the environmental model. Step 938 involves applying thefirst image to the environmental model in accordance with UV map to beused. Thus the first image is used as a texture which is applied tosegments of the environmental model in accordance with the applicable UVmap, e.g., a first UV map. The rendering may be performed separately forleft and right eye views.

In some embodiments step 938 includes step 940. In step 940 the firstimage is rendered by using the first texture map (UV map) correspondingto a first resolution allocation to apply at least a portion of thefirst image to a surface of a first portion, e.g., first segment, of themodel of the environment. For example a first set of pixels of the firstimage may be mapped to the first segment of the mesh model of theenvironment based on the first texture map. In step 942 which may beperformed in the case of stereo image playback, the second image isrendered by using the first texture map (UV map) corresponding to afirst resolution allocation to apply at least a portion of the secondimage to a surface of the first portion, e.g., the first segment, of themodel of the environment. For example a first set of pixels of thesecond image may be mapped to the first segment of the mesh model of theenvironment based on the first texture map. In optional step 944 imagesof portions of the environment not included in the first image, e.g.,the sky or ground portions, are rendered, e.g., applied to theenvironmental model in accordance with a UV map relevant to theseportions. It should be appreciated in some embodiments separate sky andground portions are not communicated with such portions being part ofthe first and second images in some embodiments.

In operation step 946, which is performed for each eye view, renderedimages corresponding to different portions of a 360 degree simulatedenvironment are combined to the extent need to provide a contiguousviewing area to a user. Step 946 is performed separately for the leftand right eye images since while the ground and sky portions may be thesame for these images when they are presented in non-stereo format, theother portions of the left and right eye images may include differenceswhich may result in the perception of depth when the left and right eyeimages are viewed by different eyes of a user of the playback device.

With the first image or pair of images having been applied to the modelof the environment in step 938 operation proceeds to display step 950via connecting node 948. In step 950 the rendered image content isdisplayed to a user of the playback device, e.g., on a display screen.In step 952 a first rendered image or a combined image generated fromrecovered first image content is displayed for viewing by one of a usersleft and right eyes or both eyes if stereoscopic display is notsupported. In step 954 which is performed in the case of stereoscopicdisplay, a second rendered image is displayed to a second one of a usersleft and right eyes. The displayed rendered second image is an imagethat was generated from recovered second image data or a combination ofrecovered, e.g., decoded second image data and data from another image,e.g., a sky or ground image portion.

With one image or pair of images having been rendered and displayed,operation proceeds to step 956 in which content corresponding to anotherimage or pair of images is received and processed. The image or imagesreceived in step 956 may be and sometimes do correspond to a secondgroup of pictures and corresponds to a different point in time than thefirst image. Thus, between the time the first image was captured and thethird image received in step 956 was captured the players, actors or anarea of motion may have shifted position from where the activity was atthe time the first image was captured. For example, while remaining in aforward field of view, the players on a field may have moved lefttriggering the sever providing the third image to use a resolutionallocation giving more resolution to the left portion of the front fieldof view than a center or right portion where the action was at the timethe first image was captured. The different resolution allocation, e.g.,a second resolution allocation by the server or encoding device, willcorrespond to specification that the playback device should use adifferent UV map, e.g., a second texture map, for rendering the thirdimage than the first image. For example, the second UV map may specifyusing fewer pixels from the third image to map to the first segment thanwere used to map from the first image to the first segment of theenvironmental map and to use more pixels from third image to map to asecond segment located in the left side of the forward field of view inthe environmental model where the action is now located at the time ofcapture of the third image than were used to map to the second segmentof the environmental map from the first frame.

Step 956 will now be discussed in detail. Step 956 includes, in someembodiments, steps 958, 960, 962, 926 and/or 968.

In step 958 a third encoded image is received. In step 960 which isoptional, a fourth encoded image is received.

In step 962 which is an alternative to steps 958, 960 an encoded frameincluding one or both of the third and fourth encoded images isreceived.

The third encoded image may be a first image of a second stereoscopicimage pair with the third and fourth images being left and right eyeimages to be displayed to a user of the playback device.

In step 956, in addition to receiving image content which can be mappedto the environmental model, in step 968 a second indicator indicatingwhich of a plurality of texture maps corresponding to differentresolution allocation is to be used with the received third and/orfourth encoded images is also received. If a new texture map indicatoris not received, in step 968 and a new texture map is not received, theplayback device will continue to use the last UV map which was beingused. Rather than receive a texture map indicator, a new texture map maybe received in step 970 which is to be used in rendering the receivedthird and/or fourth images.

With images received, e.g., in encoded form, operation proceeds fromstep 956 to step 970. In step 970 the received third and/or fourth imageor images are decoded. For example in step 974 the third encoded imageis decoded to recover a third image. In step 976 the fourth encodedimage is decoded to recover a fourth image. As discussed above, thethird and fourth images may be left and right eye views. In embodimentswhere the third and fourth images are included in a single encoded framedecoding of the received frame and separation of the third and fourthimages may be performed in step 972 to produce left and right eye imageswhich may be and sometimes are applied separately to the environmentalmap to generate separate, potentially different, left and right eyeviews.

In some embodiments the third and/or fourth images communicate acomplete 360 degree environment or panoramic view. In other embodimentsthe third and fourth images may correspond to a portion of theenvironment, e.g., a front portion or a 360 degree middle panoramicportion but not the sky and ground. In step 978 other images which aresent with the encoded third and fourth images or in a separate streammay be decoded to obtain textures for portions of the environment whichare not provided by the third and/or fourth images. In some embodimentsin step 986 a sky or ground image is obtained by decoding a receivedencoded image or frame.

With the decoding of images that were transmitted to the playback devicehaving been completed in step 972 operation proceeds to step 980 inwhich image content is rendered using the received, e.g., decoded imageor images, the UV map which was to be used in rendering the receivedimages, e.g., the second UV map, and the environmental model. Step 980involves applying the third image to the environmental model inaccordance with second UV map to be used which results in a differentallocation of pixels from the received image to the model of theenvironment than occurred when using the first UV map. Thus, as part ofthe rendering the third image is used as a texture which is applied tosegments of the environmental model in accordance with the applicable UVmap, e.g., the second UV map. The rendering may be performed separatelyfor left and right eye views.

In some embodiments step 980 includes step 982. In step 982 the thirdimage is rendered by using the second texture map (UV map) correspondingto a second resolution allocation to apply at least a portion of thethird image to a surface of the first portion, e.g., first segment, ofthe model of the environment. For example a first set of pixels of thethird image may be mapped to the first segment of the mesh model of theenvironment based on the second texture map where the first set ofpixels includes fewer pixels than the first set which were mapped whenthe first UV map was used. A second set of pixels may be mapped to asecond segment of the model where the second set of pixels includes morepixels than were mapped to the second segment when the first UV map wasused. Thus by using different UV maps to map an image to the model,different allocations of the limited number of pixels to portions of themodel of the environment may be achieved in an easy manner withouthaving to alter the number of pixels transmitted in the encoded imagesprovided to the playback device.

In step 978 which may be performed in the case of stereo image playback,the fourth image is rendered by using the second texture map (UV map)corresponding to the second resolution allocation to apply at least aportion of the fourth image to a surface of the first portion, e.g., thefirst segment, of the model of the environment. Similarly the second UVmap is used to control mapping of pixels from the fourth image to thesecond segment of the environmental model.

In optional step 986 images of portions of the environment not includedin the first image, e.g., the sky or ground portions, are rendered,e.g., applied to the environmental model in accordance with a UV maprelevant to these portions. It should be appreciated in some embodimentsseparate sky and ground portions are not communicated with such portionsbeing part of the first and second images in some embodiments.

In operation step 988, which is performed for each eye view, renderedimages corresponding to different portions of a 360 degree simulatedenvironment are combined to the extent need to provide a contiguousviewing area to a user. Step 988 is performed separately for the leftand right eye images since while the ground and sky portions may be thesame for these images when they are presented in non-stereo format, theother portions of the left and right eye images may include differenceswhich may result in the perception of depth when the left and right eyeimages are viewed by different eyes of a user of the playback device.

With the third image, which may be part of a second pair of images,having been applied to the model of the environment in step 980operation proceeds to display step 990. In step 990 the rendered imagecontent is displayed to a user of the playback device, e.g., on adisplay screen. In step 992 a third rendered image or a combined imagegenerated from recovered third image content is displayed for viewing byone of a users left and right eyes or both eyes if stereoscopic displayis not supported. In step 994 which is performed in the case ofstereoscopic display, a fourth rendered image is displayed to a secondone of a user's left and right eyes. The displayed rendered fourth imageis an image that was generated from recovered fourth image data or acombination of recovered, e.g., decoded fourth image data and data fromanother image, e.g., a sky or ground image portion.

The process of receiving and decoding images and rendering images usingthe UV map provided or specified by the server providing the imagesoccurs on an ongoing basis as represented with operation proceeding fromstep 990 back to step 914 via connecting node B 996 allowing foradditional images to be received and processed, e.g., a new first andsecond images.

In some embodiments the images correspond to a live sporting event withthe server providing the images specifying different UV maps to be usedduring different portions of the sporting event based on where theaction is occurring on the sports field with the generation of theimages to be transmitted in encoded form taking into consideration theUV map which will be used to render the images. Thus, by specifying theuse of different UV maps at different times resolution can bedynamically allocated to match where the action is occurring on a sportsfield or in an environment.

FIG. 11 which illustrates an image capture and content streaming methodin accordance with an exemplary embodiment. The method 1100 shown inFIG. 11 starts in step 1102 when it is time to capture images, e.g.,images corresponding to an event such as a sporting event or musicperformance.

From start step 1102 operation proceeds along a plurality of paths, thepaths bringing with steps 1114, 1104, 1106, 1108, 1110, 1112, which maybe performed in parallel and, optionally, asynchronously.

To facilitate an understanding of the image capture process referencewill now be made to the exemplary camera rig shown in FIG. 13. Thecamera rig 1300 can be used as the rig 102 of the FIG. 1 system andincludes a plurality of stereoscopic pairs each corresponding to adifferent one of three sectors. The first camera pair 1301 includes aleft eye camera 1302 and a right camera 1304 intended to capture imagescorresponding to those which would be seen by a left and right eye of aperson. Second sector camera pair 1305 includes left and right cameras1306, 1308 while the third sector camera pair 1309 includes left andright cameras 1310, 1312. Each camera is mounted in a fixed position inthe support structure 1318. An upward facing camera 1314 is alsoincluded. A downward facing camera which is not visible in FIG. 13 maybe included below camera 1314. Stereoscopic camera pairs are used insome embodiments to capture pairs of upward and downward images howeverin other embodiments a single upward camera and a single downward cameraare used. In still other embodiments a downward image is captured priorto rig placement and used as a still ground image for the duration of anevent. Such an approach tends to be satisfactory for many applicationsgiven that the ground view tends not to change significantly during anevent.

The output of the cameras of the rig 1300 are captured and processed bythe method of FIG. 11 which will now be discussed further. Image capturesteps shown in FIG. 11 are normally performed by operating a camera ofthe camera rig 102 to capture an image while encoding of images isperformed by encoder 112 with responses to streaming requests andstreaming of content being preformed by the streaming server 114.

In the first path of FIG. 11 which relates to downward image capture andprocessing, in step 1114 an image is captured of the ground, e.g.,beneath rig 102. This may happen prior to rig placement or during theevent if the rig includes a downward facing camera. From step 1114operation proceeds to steps 1144 where the captured image is croppedprior to encoding in step 1145. The encoded ground image is then storedpending a request for content which may be responded to by supplying oneor more encoded images in step 1146 to a requesting device.

The second processing path shown in FIG. 11 which starts with step 1104relates the processing and responding to requests for content. In step1104 monitor for request for content occurs, e g., by content server114. In step 1128 a request for content is received from a playbackdevice, e.g. device 122 located at customer premise 106.

In response to the content request the playback device is provided withinformation including one or UV maps corresponding to differentresolution allocations which may be used.

From step 1104 operation proceeds to step 1128 in which is performed incases where an environmental map was generated and/or otherenvironmental information which may be different from a predetermineddefault setting or environmental is supplied to the playback device tobe used in rendering images as part of an environmental simulation.

Thus, via step 1132 a playback device requesting content is provided theinformation need to model the environment and/or with other informationwhich may be needed to render images onto the model. In addition tomodel information step 1132 may optionally include communication of aset of UV maps to the playback device requesting content for future use,e.g., with some different UV maps corresponding to different resolutionallocations but the same area of a model in some embodiments.

In some embodiments when the FIG. 13 camera rig is used each of thesectors corresponds to a known 120 degree viewing area with respect tothe camera rig position, with the captured images from different sectorpairs being seamed together based on the images known mapping to thesimulated 3D environment. While a 120 degree portion of each imagecaptured by a sector camera is normally used, the cameras capture awider image corresponding to approximately a 180 degree viewing area.Accordingly, captured images may be subject to masking in the playbackdevice as part of the 3D environmental simulation or cropping prior toencoding. FIG. 14 is a composite diagram 1400 showing how a 3D sphericalenvironment can be simulated using environmental mesh portions whichcorrespond to different camera pairs of the rig 102. Note that one meshportion is shown for each of the sectors of the rig 102 with a sky meshbeing used with regard to the top camera view and the ground mesh beingused for the ground image captured by the downward facing camera.

When combined the overall meshes corresponding to different camerasresults in a spherical mesh 1500 as shown in FIG. 15. Note that the mesh1500 is shown for a single eye image but that it is used for both theleft and right eye images in the case of stereoscopic image pairs beingcaptured.

Mesh information of the type shown in FIG. 14 can and sometimes iscommunicated to the playback device in step 1132. The communicatedinformation will vary depending on the rig configuration. For example ifa larger number of sectors were used masks corresponding to each of thesectors would correspond to a small viewing area than 120 degrees withmore than 3 environmental grids being required to cover the diameter ofthe sphere.

Environmental map information is shown being optionally transmitted instep 1132 to the playback device. It should be appreciated that theenvironmental map information is optional in that the environment may beassumed to be a default size sphere in the event such information is notcommunicated having a predetermined number of segments arranged in aknown mesh. In cases where multiple different default size spheres aresupported an indication as to what size sphere is to be used may be andsometimes is communicated in step 1132 to the playback device.

Operation proceeds from step 1132 to streaming step 1146. Image captureoperations may be performed on an ongoing basis during an eventparticularly with regard to each of the 3 sectors which can be capturedby the camera rig 102. Accordingly, processing paths starting with steps1106, 1108 and 1110 which correspond to first, second and third sectorsof the camera rig are similar in terms of their content.

In step 1106, the first sector pair of cameras is operated to captureimages, e.g., a left eye image in step 1116 and a right eye image instep 1118. FIG. 16 shows an exemplary image pair 1600 that may becaptured in step 1106. The captured images are then cropped in step1134, e.g., to remove undesired image portions such as image portionscaptured by another camera pair. In step 1144 a resolution allocation tobe used for the captured left and right eye image is determined, e.g.,selected. The selection may be based in information about which portionof the environment and thus captured images was important at the time ofthe capture of the images. The importance information may be based ondetection of where individuals at the event being videoed are looking atthe time of image capture, system controller input and/or the locationof motion in the environment at the time of image capture. A resolutionreduction operation is performed on the captured images in step 1146based on the determined, e.g., selected, resolution allocation. Theselected resolution allocation may be one of a plurality of supportedresolution allocations corresponding to different supported UV mapscorresponding to the portion of the environment captured by the firstsector camera pair. In step 1148 the reduced resolution images generatedin step 1146 are encoded. Information indicating the UV map to be usedfor rendering the reduced resolution images generated in step 1146 isgenerated in step 1149 and will, in some embodiments be associated withand transmitted with the encoded images generated in step 1146 so thatthe playback device can determine which UV map to use when renderingimages recovered by decoding the encoded images generated in step 1146.

FIG. 17A shows an exemplary mesh model 1700 of an environment inaccordance with the invention.

FIG. 17B shows a UV map 1702 which can be used to map portions of a 2Dimage onto surfaces of the mesh model shown in FIG. 17A.

FIG. 18 shows an exemplary result 2000 of cropping the left and righteye view images of FIG. 16 as may occur in step 1134. The cropping ofimage pair shown in FIG. 18 may be performed prior to encoding andtransmission to one or more playback devices.

The image capture, cropping and encoding is repeated on an ongoing basisat the desired frame rate as indicate by the arrow from step 1149 backto step 1106.

Similar operations to those described with regard to the images capturedfor the first camera pair are performed for the images captured by thesecond and third sector camera pairs.

In step 1172 the encoded images generated from the captured images arestreamed to a playback device along with the information indicating theUV maps to be used in rendering the encoded images being streamed. Insome embodiments before a UV map is used it is communicate in thecontent stream prior to the encoded image for which it is beingsupplied. Thus in some embodiments rather than being supplied with theUV maps via a separate channel or set of information in some embodimentsthe UV maps are embedded in the content stream used to deliver theencoded images to requesting playback device or devices.

FIG. 12 illustrates a method 1200 of operating a playback device orsystem, which can be used in the system of FIG. 1, in accordance withone exemplary embodiment. The method 1200 beings in start step 1202. Instep 1204 the playback device transmits a request for content, e.g., tothe streaming server of FIG. 1. The playback device then receives instep 1206 various information which may be used for rendering images.For example environmental model information may be received in step 1206as well as one or more UV maps corresponding to different resolutionallocations for one or more regions of the environment. Thus, in step1206, the playback device may receive environmental model and/or UV mapinformation corresponding to different resolution allocations. Theinformation received in step 1206 is stored in memory for use on an asneeded basis.

Operation proceeds from step 1206 to step 1208 in which one or moreimages are received, e.g., image captured of an environment to besimulated while an event was ongoing in the environment. In step 1210information indicating which UV maps are to be used for rendering theone or more received images is indicated. In some embodiments theinformation indicates which UV map in a set of UV maps corresponding todifferent resolution allocation which may have been used for a portionof the environment is to be used for rendering left and right eye imagesof a frame pair, e.g., corresponding to a front portion of anenvironment. In step 1212 one or more of the received images aredecoded.

Operation proceeds from step 1212 to steps 214 in which the decodedimages corresponding to surfaces of the environmental model are appliedusing one or more UV maps corresponding to the indicated resolutionallocation that was used to generate the decoded image or images.Operation proceeds from steps 1214 to step 1218 in which image areascorresponding to different portions of the 360 degree simulatedenvironment are combined to the extent needed to generate a contiguousimage of a viewing area to be displayed. Then in step 1220 the imagesare output to a display device with, in the case of stereoscopic imagecontent, different images being displayed to a user's left and righteyes. Operation process from step 1220 back to step 1204 with contentbeing requested, received and processed on an ongoing basis.

FIG. 19 is a drawing 2100 that illustrates mapping of an image portioncorresponding to a first sector to the corresponding 120 degree portionof the sphere representing the 3D viewing environment.

In step 1216, images corresponding to different portions of the 360degree environment are combined the extent needed to provide acontiguous viewing area to the viewer, e.g., depending on head position.For example, ins step 1218 if the viewer is looking at the intersectionof two 120 degree sectors portions of the image corresponding to eachsector will be seemed and presented together to the viewer based on theknow angle and position of each image in the overall 3D environmentbeing simulated.

FIG. 20 is an illustration 2200 showing the result of applying texturesto mesh models to form a complete 360 degree view of an environmentwhich may be presented to a user viewing the environment from theperspective of being located in the center of the illustratedenvironment and with the images applied to the inside of the sphericalenvironment. The result of the simulation and display is a completeworld effect in which a user can turn and look in any direction.

The mapped images are output to a display device in step 1220 forviewing by a user. As should be appreciated the images which aredisplayed will change over time based on the received images and/orbecause of changes in head position or the user selected viewerposition.

Methods and apparatus for supporting delivery, e.g., streaming, of videoor other content corresponding to an environment are described. In someembodiments the images corresponding to the environment which arecommunicated to a playback device exceed the area a user can view at agiven time so that content is available in the event the user changeshis/her viewing angle by, for example, moving his/her head. By providingimages for an environmental area larger than that which can be viewed bya user at a given time the playback device has enough information toprovide images should the user's viewing angle change without theplayback device having to wait for new images or other contentcorresponding to a portion of the environment which the user was notpreviously viewing.

In at least some embodiments the environment is represented using amesh. Images are captured and encoded into frames, e.g., frames intendedfor viewing by a left eye and frames intended to be viewed by a righteye. While the techniques are described in the context of 3Dstereoscopic applications, the methods can be used for stereoscopicviewing as well with a single stream of frames being communicated ratherthan a stream of frame pairs.

In some embodiments the techniques are used to communicate imagescorresponding to a 360 degree viewing area. However, the techniques maybe used for communicating images corresponding to less than a 360 degreeviewing area, e.g., with a single frame communicating image contentcorresponding to the 360 degree viewing area. The methods and apparatusof the present invention are particularly well suited for streaming ofstereoscopic and/or other image content where data transmissionconstraints may make delivery of 360 degrees of content difficult todeliver at the maximum supported quality level, e.g., using best qualitycoding and the highest supported frame rate. However, the methods arenot limited to stereoscopic content.

In various embodiments images corresponding to a 360 degree or otherarea are captured and combined to form an image of the area. Thedifferent portions of the image content of the area, e.g., a 360 degreeenvironment, are mapped to a frame which is to be encoded andtransmitted. Separate frames may be generated and transmitted for eachof the left and right eye views. While the image content correspondingto different portions of the area may have been captured at the sameresolution, the mapping of the captured images to the frame may, and insome embodiments is, different for different areas of the environment.For example, the front view portion of the environment may be preservedat full or near full resolution, with the sides and back beingincorporated into the frame at lower resolutions. Images correspondingto the top and bottom of a 360 degree environment may be incorporatedinto the frame at a different, e.g., lower, resolution than the frontand/or side views. In some embodiments images corresponding to the topand bottom of an environment are sent separately and, in many cases, asstatic images or at a different rate than images corresponding to theother portions of the environment.

As a result of the mapping process, a frame communicating an environmentmay use different numbers of pixels to represent the same size area of aphysical environment. For example, a larger number of pixels may be usedto represent a forward viewing area with a lower number of pixels beingused to represent a rear viewing area. This represents selectivedownsampling at the time of generate a frame representing the multipleimage areas.

In a decoder a the image is mapped or wrapped onto a 3D model of theenvironment as part of the display process in some embodiments. The mapis sometimes referred to as a UV map since UV coordinates are used inmapping the two dimensional frame that is communicated to XYZ space of a3D model of the environment. The grid (UV map) used to map thetransmitted frame to the 3D model takes into consideration the reducedresolution used in some embodiments for the back and side portions ofthe environment.

In various embodiments, the map used to wrap a communicated frame untothe model of the environment may change to reflect the differentallocations of resolution to different portions of the environment. Forexample, portions of the environment having high motion may be allocatedmore resolution at points in time when there is high motion and lessresolution at other times.

Information on how the transmitted frame should be processed by thedecoder to take into consideration the allocation of different amountsof resources, e.g., pixels, to different image areas at different pointsin time is communicated to the playback device and used to interpret thecommunicated frame and how it should be applied to the 3D environment.

The method used in various embodiments may be referred to as use ofselective resolution allocation in a Panoramic Image map. This approachallows the encoder and playback device to use a UV map to optimize theresolution in a equi rectangular projection so that more of the limitednumber of pixels available in a communicated frame are used for the moreimportant image element(s) and pixels aren't wasted on image areas oflow importance. The methods and apparatus are particularly well suitedfor devices with limited pixel buffers, such as phones where every pixelis precious because of the phones fairly limited pixel buffer which isavailable for decoding images.

The process of selective resolution allocation in a panoramic image mapcan be understood when FIG. 21 is considered. FIG. 21 shows a 3D meshmodel 2300 of an environment onto which captured images are to bewrapped as part of the process of rendering an image on a displaydevice. The 3D model 2300 includes a sky mesh 2300, a 360 degreepanoramic mesh 2308 and a ground mesh 2310. As part of the process ofcommunicating images corresponding to the 3D environment represented bythe 3D model, a frame representing an image of the sky is transmitted. Amap is used to determine which parts of the transmitted frame areapplied to which segments of the sky mesh. In at least one embodimentthe sky map includes one segment for each segment of the sky mesh andprovides a method of determining which portion of a frame representingan image in what is sometimes referred to as UV space will map to thesegments of the sky mesh 2306. In some embodiments the framerepresenting the image of the sky is sent once and is thus static orsent at a low rate much less frequently than images to be mapped to the360 degree panoramic mesh portion of the model 2300.

As part of the process of communicating images corresponding to the 3Denvironment represented by the 3D model, a frame representing an imageof the ground is transmitted. A ground map is used to determine whichparts of the transmitted frame are applied to which segments of theground mesh. In one embodiment the ground map includes one segment foreach segment of the ground mesh 2310 and provides a method ofdetermining which portion of a frame representing an image in what issometimes referred to as UV space will map to the segments of the groundmesh 2310. In some embodiments the frame representing the image of theground is sent once and is thus static or sent at a low rate much lessfrequently than images to be mapped to the 360 degree panoramic meshportion of the model 2300.

Of particular importance are frames corresponding to the 360 degree meshportion since this includes the areas of the environment which tend tobe most frequently viewed. While the image of this environmental areamay be captured at a consistent resolution as represented by the uniformsegments of the uncompressed panoramic image map 2302, different areasto which the panoramic image and panoramic mesh correspond may be ofdifferent amounts of importance at different times. For example, frontalareas were the main action is ongoing and/or areas with high motion maybe important to represent in detail while other environmental areas maybe less important. The uniform allocation of limited resources in termsof pixels of a frame to different areas of an environment is wastefulwhen the importance of the different image areas is taken intoconsideration along with the fact that the pixels of the frame are alimited resource. In order to make efficient use of the available pixelsof a frame to communicate an image corresponding to a 360 degreeenvironment, a map may be used to allocate different numbers of pixelsto different portions of the 360 degree mesh. Thus some portions of themesh 2308 may be coded using more pixels than other portions. Inaccordance with one such embodiment, a panoramic image map 2304 withnon-uniform segments sizes may be used. While in the case of the FIG. 21map each segment of the map will be used to map pixels of a receivedframe to a corresponding segment of the panoramic mesh 2308, somesegments will use more pixels from the transmitted image than othersegments. For example, mode pixels will be allocated to the middleportions of the panoramic mesh in the FIG. 21 example as represented bythe larger segment sizes towards the middle of the map 2304 than towardsthe top and bottom of the map 2400. While the map 2304 is used to mapportions of a received frame to the mesh 2308, prior to encoding of thecommunicated frame one or more segments of the uncompressed image ofrepresenting the panoramic environment will be downsampled taking intoconsideration the panoramic image map. For example, portions of anuncompressed image representing the top and bottom portions of theenvironment will be downsampled to reflect the small number of pixelsallocated in the panoramic image map for representing such imageportions while other portions may be subject to lower or nodownsampling.

The panoramic image map is generated in some embodiments based on sceneanalysis and/or taking into consideration a user viewing position. Thepanoramic image map may be and in some embodiments is changed over timeas the location of the main action changes, e.g., ball position during asporting event in a stadium environment changes. The change is normallylimited to occur on a group of pictures boundary within a video streamand/or upon a scene change boundary such as a boundary associated withthe start or end of a commercial break in a video sequence. The new mapto be used for interpreting frames may be transmitted at a playbackdevice with or prior to a frame which is constructed taking intoconsideration the new map. Alternatively the playback device may so avariety of predetermined maps which may be used for mapping receivedframes to the mesh model of the environment and the video stream mayinclude information indicating which of the plurality of maps is to beused for a particular set of communicated frames.

The selective allocation and varying of the image map to take intoconsideration content and/or user viewing position, can be applied to afull 306 degree area or some small portion of the environment.Accordingly, while shown with an example that maps a frame to a 360degree environmental area the same method may be applied to a map thatis used to map a frame to a 180 degree image area or some other portionof a 360 degree environment. While the map used to map an image tocorresponding segments of a 3D model may change, the model need notchange. However, changes in the model may be made to reflect changes inthe environment, e.g., when a stage is moved and/or other changes in theenvironment are detected. Thus, both map and model changes are possible.

While different resolution allocations to the top and bottom portions ofan area, e.g., the panoramic 360 degree middle area may be made,different resolution allocations may be made within a horizontal area ofthe environment.

For example, at different times it may be desirable to allocatedifferent amounts of resolution to different portions of a sports fielddepending on where the ball or area of action is located.

FIG. 21 shows how selective resolution can be used with regard to animage, e.g., frame, which maps to an environmental grid correspondingto, for example, a 360 spherical panoramic mesh. Separate images may becommunicated for applying as textures to the sky and ground meshportions of the world model shown in FIG. 21.

The panoramic image 2302 prior to compression, corresponding to the 360degree panoramic mesh 2308 includes image content at a generally uniformresolution in the example. In an actual embodiment it should beappreciated that the use of a fisheye lens may introduce somedistortions and thus differences in resolution due to lens issues.However, for purposes of explaining the invention it will be presumedthat image capture results in an image with a uniform resolution. Thegrid applied to the panoramic image 2302 is uniform and if used as a UVmap would result in uniform resolution allocation to the segments of the360 degree panoramic portion of the mesh model 2308. However, since auser is less likely to be looking at the bottom or top portions of theenvironment corresponding to the 360 degree panoramic mesh area, priorto encoding and transmission to the playback device the upper and lowerportions are subject to a resolution reduction operation and the UV mapto be used during playback is adjusted accordingly. Thus, in mesh 2304which represents a UV map to be used to render a resolution adjustedimage corresponding to the 360 panoramic area of the mesh model, thegrid sizes are smaller. Thus, when applied fewer pixels will beextracted for a top segment from the source image and applied to thecorresponding segment of the environment than will be extracted andapplied for a segment corresponding to the middle horizontal portion ofthe 360 panoramic mesh model. Thus the UV model takes into considerationthe selective allocation of resolution applied to the captured imagerepresenting the 360 panoramic area.

The playback device will use the UV mesh which reflects the resolutionreduction applied to an image prior to transmission to the playbackdevice when rendering the received image, e.g., applying the receivedimage as a texture, onto the surface of the environmental model, e.g.,mesh model of the environment.

While a static UV map reflecting a resolution reduction operation may beand is used in some embodiments, it may be desirable in at least someembodiments where the portion of the environment with the highestpriority may change to support the dynamic selection of a resolutionallocation approach to use and to use a UV map corresponding to theselected resolution allocation. In such a way, resolution allocation maybe changed to reflect which portion of the environment is given priorityin terms of resolution at a given time.

FIG. 22 represented by reference number 2400, shows a first capturedimage 2402 of a first portion of an environment. Each large dotrepresents a pixel. The image 2402 is of uniform resolution asrepresented by the 4 pixels in each square grid area. Small dots areused to indicate that the image continues and extends toward the otherillustrated portions of the image 2402. When a first resolutionallocation is selected, e.g., a resolution which gives priority to themiddle portion of the image 2402, resolution will be preserved duringthe middle portion of the image 2402 but reduced for the left and rightportions. Such a resolution allocation may be desirable where, forexample, the image 2402 is of a sports field and the action is at thecenter portion of the sports field when image 2402 is captured. Arrowsextending from image 2402 towards reduced resolution image 2404represent the application of a first selective resolution reductionoperation to image 2402 to generate image 2404. The first resolutionreduction operation may involve a downsampling applied to the left andright portions of image 2402 but not the middle portion. The grid shownas being applied to image 2404 represents the resolution allocation usedto generate image 2404 from image 2402. As can be seen the firstresolution adjusted image 2404 includes half as many pixel in the twoleft and right most rows of the image as did image 2402 but the samenumber of pixels for segments towards the center portion of the image2404. Grid 2406 represents a first UV map corresponding to the firstresolution allocation which is suitable for mapping segments of theimage 2404 to segments of the model of the environment.

FIG. 23 represented by reference number 2500, shows a first capturedimage 2502 of the first portion of the environment. As in the case ofFIG. 22, each large dot represents a pixel. The image 2502 is of uniformresolution as represented by the 4 pixels in each square grid area.Small dots are used to indicate that the image continues and extendstoward the other illustrated portions of the image 2502. When a secondresolution allocation is selected, e.g., a resolution which givespriority to the left and middle portions of the image 2502, resolutionwill be preserved in the left and middle portions of the image 2502 butreduced for the right portion. Such a resolution allocation may bedesirable where, for example, the image 2502 is of a sports field andthe action is at the left portion of the sports field when image 2502 iscaptured. Arrows extending from image 2502 towards reduced resolutionimage 2504 represent the application of a second selective resolutionreduction operation to image to generate image 2504. The secondresolution reduction operation may involve a downsampling applied to theright portion of image 2502 but not the left or middle portions. Notethat the area to which the downsampling is applied is of a size equal tothe area to which downsampling was applied in FIG. 22. As a resultimages 2404 and 2504 will have the same total number of pixels but withthe resolution being different in different areas of the images 2404,2504.

While total pixel count is maintained as being constant for differentreduced resolution images with the resolution allocation applying todifferent areas of an image, this is not critical and different imagesmay include different numbers of pixels after a resolution reductionoperation. However, keeping the pixel count constant facilitatesencoding since the encoder can treat the images to be encoded as beingof the same size even though when used in playback device differentportions of the model will be rendered at different resolutions due tothe use of different UV maps for different resolution allocations.

The grid shown as being applied to image 2504 represents the resolutionallocation used to generate image 2504 from image 2502. As can be seenthe second resolution adjusted image 2504 includes half as many pixel inthe four right most rows of the image as did image 2502 but the samenumber of pixels for segments towards the left and center portions.

Grid 2506 represents a first UV map corresponding to the firstresolution allocation which is suitable for mapping segments of theimage 2504 to segments of the model of the environment.

FIG. 24 represented by reference number 2600, shows a first capturedimage 2602 of the first portion of the environment. As in the case ofFIGS. 22 and 23, each large dot represents a pixel. The image 2602 is ofuniform resolution as represented by the 4 pixels in each square gridarea. Small dots are used to indicate that the image continues andextends toward the other illustrated portions of the image 2602. When athird resolution allocation is selected, e.g., a resolution which givespriority to the middle and right portions of the image 2602, resolutionwill be preserved in the middle and right portions of the image 2602 butreduced for the right portion. Such a resolution allocation may bedesirable where, for example, the image 2602 is of a sports field andthe action is at the right portion of the sports field when image 2602is captured. Arrows extending from image 2602 towards reduced resolutionimage 2604 represent the application of a third selective resolutionreduction operation to image to generate image 2604. The thirdresolution reduction operation may involve a downsampling applied to theleft portion of image 2602 but not the right or middle portions. Notethat the area to which the downsampling is applied is of a size equal tothe area to which downsampling was applied in FIGS. 22 and 24. As aresult images 2604 will have the same total number of pixels as images2404, 2504 but with the resolution being allocated differently in termsof the portion of the environment to which higher resolution isallocated.

The grid shown as being applied to image 2604 represents the resolutionallocation used to generate image 2604 from image 2602. As can be seenthe third resolution adjusted image 2604 includes half as many pixel inthe four left most rows of the image as did image 2602 but the samenumber of pixels for segments towards the right and center portions.

Grid 2606 represents a first UV map corresponding to the firstresolution allocation which is suitable for mapping segments of theimage 2604 to segments of the model of the environment.

UV map 2406 is communicated to a playback device for use with an imagegenerated suing the first resolution allocation. UV map 2406 iscommunicated to a playback device for use in rendering an imagegenerated using the second resolution allocation and UV map 2606 iscommunicated to the playback device for use in rendering an imagegenerated using the third resolution allocation. The streaming systemand the playback system both store the set of UV maps 2406, 2506, 2606with the streaming system indicating which UV map should be applied towhich image and the rendering device, e.g., playback device, using theindicated UV map associated with a received image.

While different resolution allocation are supported through the use ofdifferent UV maps this can be transparent to the decoder in the playbackdevice which decodes received images since the decoder need not haveknowledge of which of the plurality of possible resolution allocationswere used to generate a received encoded image which is to be decoded bythe decoder in the playback device.

FIG. 25 which comprises FIGS. 25A and 25B illustrates an exemplarymethod 2900 of operating a content processing and delivery system inaccordance with an exemplary embodiment. FIG. 25A shows the first partof method 2900. FIG. 25B shows the second part of method 2900. Themethod 2900 shown in FIG. 25 starts in step 2902 with the contentprocessing and delivery system being initialized to process and delivercontent, e.g., image content and/or information used to render images.In some embodiments the method of flowchart 2900 is performed using thecontent delivery and processing system 700 of FIG. 7.

From start step 2902 operation proceeds to steps 2904 and 2906, whichmay be performed in parallel and, optionally, asynchronously. In variousembodiments customer rendering and playback devices are provided withinformation that can be used in rendering of image content and/orproviding 3D playback experience to the viewers. In some embodimentsthis includes providing environmental model and/or other environmentalinformation to the customer devices to be used in rendering images aspart of an environmental simulation. In step 2904 a 3D environmentalmodel and/or information that can be used to model is communicated toone or more customer devices. In some embodiments the model is a meshmodel of the environment from which one or more images are captured. Insome embodiments additional information which can be used in renderingimages, e.g., one or more UV maps are also communicated to the customerdevices, e.g., content playback devices, in step 2905. The UV mapscorrespond to different resolution allocations with different UV maps,also referred to as texture maps, providing different mappings of pixelsof transmitted images to segments of the environmental model. If the UVmaps are communicated in step 2905 they can later be identified whenthey are to be used to map a transmitted image and need not beretransmitted multiple time to the playback device. However, in someembodiments a set of UV maps is not communicated in step 2905 and anapplicable UV map is transmitted with or prior to communication of animage to which the UV map is to be applied and used.

In some embodiments the information in steps 2904 and 2905 iscommunicated once, e.g., prior to communicating actual image content tothe customer devices. While environmental map information and/orenvironmental models may be communicated to the playback device in someembodiments where such information is generated and/or available at theserver side, in some other embodiments the environment may be assumed tobe a default size and shape, e.g., a sphere or half sphere and in such acase the default environmental module and/or UV maps may be preloaded inthe playback device and need not be transmitted by the server.

The processing of image content begins in step 2906 which can beperformed in parallel with steps 2904, 2905. In step 2906 image contentis received by the processing system, e.g., content delivery system 700shown in FIG. 7. The image content received in step 2906 may be from animage capturing device such as the ones discussed in the applicationsuch as the one shown in FIG. 13. In some embodiments the step 2906 ofreceiving image content includes step 2908 wherein a first imagecorresponding to a first portion of an environment, e.g., environment ofinterest where images are captured, is received. In some embodiments thefirst image is one image of an image pair that also includes a secondimage, with the first image being one of a left and right eye imagepair, the second image being a second one of a left and right eye imagepair. In some such embodiments the first and second images are receivedas part of the image pair in step 2906. Thus in some such embodimentsstep 2906 further includes step 2910 of receiving the second image.

Operation proceeds from step 2906 to step 2912 the system selects afirst resolution allocation to be used for at least one imagecorresponding to a first portion of the environment. This selection maybe and sometimes is based on detection of motion in the received imagecontent, the location of particular objects such as a sports jersey,and/or human input indicating which portion of the captured image is tobe given priority and preserved at a higher resolution during encoding.For example, detection of player's jerseys or uniforms may indicateareas to be preserved at high resolution in which case a resolutionallocation which preserves the areas where the uniforms are detected mayand in some embodiments will be selected. Other portions of the imagemay be and sometimes are subject to down sampling. Each resolution maycorrespond to a particular UV map which is intended to be used formapping images produced by using a particular corresponding resolutionallocation.

Operation proceeds from step 2912 to step 2914. In step 2914 in which itis determined if the selected first resolution allocation is differentfrom a previously selected resolution allocation, e.g., indicative of achange in down sampling and UV map. The selected first resolutionallocation may be one of a plurality of supported resolution allocationscorresponding to different supported UV maps corresponding to the firstportion of the environment captured in the first image. In accordancewith one aspect from the plurality of supported resolution allocations aresolution allocation may be selected at a given time to process acurrent image and/or group of images. If it is determined that theselected first resolution allocation is different than the previouslyselected resolution allocation the operation proceeds from step 2914 tostep 2916 where new downsampling and/or filtering informationcorresponding to the newly selected resolution allocation used tocontrol resolution reduction is loaded and then operation proceeds tostep 2918. If in step 2914 it is determined that the selected firstresolution allocation is the same as the previously selected resolutionallocation (or is the same as a default allocation if no previousselection was made) then there is no need for new down sampling and/orfiltering information to be loaded and thus the operation proceedsdirectly to step 2918. The selected resolution allocation for an imageindicates how down sampling is to be applied to an image which is to beencoded and transmitted to the playback device.

In step 2918 a resolution reduction operation, e.g., downsampling, isperformed on the first image of the first portion of the environment inaccordance with the selected first resolution allocation to generate afirst reduced resolution image 2919. The first reduced resolution image2919 which is the output of step 2918 includes at least some imageportions having different resolutions.

Operation proceeds from step 2916 to step 2920 in embodiments wherepairs of images are processed, e.g., stereoscopic image pairs includingleft and right eye views. In step 2920 a resolution reduction operationis performed on the second image of the first portion of theenvironment, e.g., the second image in stereoscopic image pair, inaccordance with the selected first resolution allocation to generate asecond reduced resolution image 2921. The second reduced resolutionimage 2921 which is the output of step 2918 includes at least some imageportions having different resolutions. Thus, where stereoscopic imagepairs are processed, both the left and right eye images of a pair willbe subject to the same resolution reduction operation.

While step 2920 is shown as being performed after step 2918 it may beperformed in parallel with step 2918 simultaneously. The data output ofsteps 2918 and 2920, e.g., the generated first and second reducedresolution images 2919 and 2921, serve as inputs to the next step 2922.In the case of non-stereo image content, a single image will beprocessed and the second image will not be present.

In step 2922 the reduced resolution image 2919 and/or reduced resolutionimage 2921 are encoded. In step 2924 the first reduced resolution imageis encoded. In step 2926 the second reduced resolution image, whenpresent, is encoded.

Operation proceeds from step 2922 to step 2928. In step 2928 the encodedreduced resolution images are stored in memory, e.g., for subsequentcommunication, e.g., streaming to a content playback device, e.g.,located at a customer premises such as a house or home. Operationproceeds from step 2928 to step 2930 via connecting node B 2929. In step2930 the encoded reduced resolution image(s) are communicated to aplayback device. This may involve transmitting, e.g., streaming, theimages to the playback device over a wired network, cable network orwireless network or some other type of network. Step 2930 includes steps2932 and step 2934. In step 2932 the first reduced resolution image iscommunicated to the customer playback device, e.g., in encoded form andin step 2934 in the second reduced resolution image is communicated tothe playback device, e.g., in encoded form. Step 2934 is performed whena stereo pair of images is communicated, e.g., in a single frame or pairof frames.

Operation is shown proceeding from step 2930 to step 2936. Howeverdepending on the embodiment step 2936 may precede step 2930. In step2936 a texture map, e.g., first texture map, to be used to map theencoded images to the model of the environment is indicated or providedto the playback device. The identification of the first texture map maybe sufficient where the first texture map, e.g., UV map, was alreadyloaded into the playback device e.g., as part of step 2905. Based on thecommunicated information and/or map, the playback device knows that itis to use the first UV map with the first and second images which wereproduced using the first resolution allocation to which the first UV mapcorresponds. The first UV map may be used by the playback device torender other images which are also produced in accordance with the firstresolution allocation. In some embodiments a resolution allocation ismaintained for a group of pictures and thus the same UV map may be usedfor multiple consecutive images in such embodiments.

Operation proceeds from step 2936 in which the playback device isprovided information about what texture map to use while rendering thefirst and second images to step 2938 which relates to processing of anadditional image or images, e.g., a third image and/or forth image. Thethird and/or fourth image may be and in some embodiments are left andright images of a second stereoscopic image pair or some other image orimages of the environment captured after the first image.

In step 2940 a second resolution allocation is selected to be used forthe received images, e.g., third and/or fourth images. The resolutionallocation may be determined using the same techniques used to determinethe first resolution allocation, e.g., identifying an area or areas ofimportance based on motion, presence of an object such as sports jersey,ball, etc. Once the second resolution allocation is selected from theset of resolution allocations, e.g., each corresponding to a differentUV map, operation proceeds to step 2942. In step 2942 a check is made todetermine if the second resolution allocation is different from thefirst resolution allocation. The second resolution allocation may bedifferent, e.g., because the ball or players may have moved to adifferent portion of the field since the first image was captured. Ifthe second selected resolution allocation is different than the firstselected resolution allocation new downsampling information needs to beloaded and used and operation proceeds to step 2944. In step 2944 thenew downsampling and/or other resolution allocation information isloaded so that it can be used in the resolution reduction step 2946. Ifin step 2942 it is determined that the second resolution allocation isthe same as the first, the processor of the system implementing themethod 2900 already knows the downsampling to be preformed since it wasused process the first image and need not load new downsamplinginformation and operation proceeds to step 2946.

In step 2946 a resolution reduction operation, e.g., downsampling, isperformed on the received third and/or fourth image to produce reducedresolution versions of the third and/or fourth images 2947. Operationproceeds from step 2946 to step 2948 in which the reduced resolutionthird and/or fourth images are encoded prior to being communicated,e.g., transmitted, to the playback device in step 2950.

In step 2952, which is shown being performed after step 2950 but whichmay and sometimes does precede step 2950 or occur in parallel with step2950, the information indicating the UV map to be used for rendering thethird and fourth images is communicated to the playback device. This mayinvolve sending the UV map to be used to the playback device or simplyidentifying a previously stored UV map. Since the third and fourthimages were generated using the second resolution allocation theinformation will identify the UV map corresponding to the second UVallocation. Operation proceeds from step 2952 via connecting node 2954to step 2906 where additional image content is received, e.g., from acamera device, and treated as new first and second images.

Over time a sequence of images representing view may be received andprocessed with the resolution allocation used at a given time dependingon the received image content and/or user input. Over time as differentresolution allocations are used, the content playback device will besignaled to use different corresponding UV maps. Thus when the secondresolution allocation is different from the first resolution allocationthe playback device will be instructed to use a second different UV mapto render images generated in accordance with the second resolutionallocation which is different from a first UV map used to render imagesgenerated in accordance with the first resolution allocation. A largenumber of different resolution allocations can be used in combinationwith corresponding UV maps allowing for a wide variety of differentresolution allocations to be supported.

FIG. 26 illustrates an exemplary embodiment of a content playback method2700 which may be, and in some embodiments is, implemented on exemplarycomputer system/content playback device 800. The method 2700 may be usedby a device which receives content encoded and transmitted in accordancewith the method of FIG. 25.

For explanatory purposes, the exemplary content playback method 2700will be explained in connection with the playback device 800 shown inFIG. 8. It should be appreciated that the method 2700 can be implementedon other apparatus. The exemplary playback method 2700 begins in startstep 2702 from which operation proceeds to step 2704.

In step 2704, the receiver 860 of the network interface 810 of thecontent playback device 800 receives a mesh model of an environment.Operation proceeds from step 2704 to step 2706. In step 2706, thereceiver 860 of the network interface 810 of the content playback device800 receives one or more image maps, e.g., one or more image UV maps,indicating a mapping between an image and the mesh model of anenvironment. In some embodiments, step 2706 includes sub-step 2708and/or sub-step 2710. In sub-step 2708, the receiver 860 of the networkinterface 810 of the content playback device 800 receives a first imagemap. In sub-step 2710, the receiver 860 of the network interface 810 ofthe content playback device 800 receives a second image map. Operationproceeds from step 2706 to step 2712.

In step 2712, the content playback device 800 stores the received imagemap or maps in a storage device, e.g., memory 812. For example, UV MAP 1836 and UV MAP 2 836 are stored in memory 812. In some embodiments thereceived image maps are stored in a storage device coupled to thecontent playback device 800. Operation proceeds from step 2712 to step2714.

In step 2714, the receiver 860 of the network interface 810 receives anencoded image. Operation proceeds from step 2714 to step 2716. In step2716, the decoder 864 of the playback device 800, decodes the receivedencoded image. In some embodiments, a hardware decoder module decodesthe received encoded images. In some embodiments, the processor 808executing instructions from decoder module 820 decodes the receivedencoded image. Operation proceeds from step 2716 to step 2718.

In step 2718, the decoded image is mapped to the mesh model of theenvironment in accordance with the first image map to produce a firstrendered image. The first image map mapping different numbers of pixelsof the decoded image to different segments of the mesh model of theenvironment. While the mapping of the different numbers of pixels of thedecoded image to different segments of the mesh model of the environmentmay occur in a variety of different ways, in some embodiments, thedifferent numbers of pixels are mapped to environmental regions of thesame size but located at different locations in the environment. In somesuch embodiments, segments in the environment corresponding to actionare allocated more pixels than segments in which less or no action isdetected. In some embodiments, at least some segments corresponding to afront viewing area are allocated more pixels per segment than segmentscorresponding to a rear viewing area. This mapping may be, and in someembodiments is, performed by the processor 808 of the playback device800. Operation proceeds from step 2718 to step 2719.

In step 2719, the first rendered image is displayed for example ondisplay 802 of content display device 800.

In some embodiments, operation proceeds from step 2719 to step 2720. Instep 2720, the receiver 860 of the network device 810 of the playbackdevice 800 receives a signal indicating that a second image map shouldbe used to map portions of received frames to the environmental meshmodel. In some embodiments the decoded image is a frame. Operationproceeds from step 2720 to optional step 2722. In step 2722, in responseto receiving the signal indicating that a second image map should beused to map portions of received frames to the environmental mesh model,a second image map is used to map portions of received frames to theenvironmental mesh model to produce one or more additional renderedimages, e.g., a second rendered image. In some embodiments, the secondimage map is the second image map received in step 2710.

In some embodiments, the first image map allocates a first number ofpixels of a frame to a first segment of said environmental mesh modelwherein the decoded image is a frame and said second image map allocatesa second number of pixels of the frame to the first segment of saidenvironmental mesh model, the first and second number of pixels beingdifferent. The mapping of step 2722 may be, and in some embodiments is,performed by the processor 808 of the playback device 800. Operationproceeds from optional step 2722 to optional step 2724.

In step 2724, the additional rendered image(s), e.g., the secondrendered image, is displayed for example on display 802 of contentdisplay device 800. Operation proceeds from step 2724 to step 2704 wherethe method continues as previously described.

In some embodiments of the exemplary method 2700, the received meshmodel of an environment is stored in a storage device, e.g., 3Denvironmental mesh model 832 stored in memory 812 of the playback device800. In some embodiments, the received encoded image data which may be,and in some embodiments are encoded scene portions, is stored in astorage device, e.g., received encoded data 824 stored in memory 812 ofthe playback device 800. In some embodiments, the decoded image data isstored in a storage device, e.g., decoded data 826 stored in memory 812of the playback device 800. In some embodiments, the one or more of therendered images are stored in a storage device, e.g., memory 812 of theplayback device 800. In some embodiments, the first and second imagesare rendered by the processor 808 executing instructions contained inthe image generation module 822. In some embodiments, a hardware, e.g.,circuits, image generation module performs the operation of renderingthe one or more images, e.g., the first and/or second rendered images.

The exemplary embodiment of method 2800 of communicating information tobe used to represent an environment will now be described in connectionwith FIG. 10. The exemplary method 2800 may be, and in some embodimentsis, implemented by a content delivery system such as for example contentdelivery system 700 illustrated in FIG. 7.

Operation of the method 2800 begins in start step 2802. Operationproceeds from step 2802 to step 2804.

In step 2804, a first image map to be used to map portions of a frame tosegments of an environmental model are communicated, e.g., to a contentplayback device such as for example content playback device 800illustrated in FIG. 8. The first image map allocates different sizeportions of the frame to different segments of the environmental modelthereby allocating different numbers of pixels to different segments ofthe environmental model. In some embodiments, the network interface 710of the content delivery system 700 performs this operation. In suchembodiments, the network interface 710 includes a transmitter 711 whichperforms this function. Operation proceeds from step 2804 to step 2806.

In step 2806, a first frame including at least a portion of a firstimage to be mapped to the environmental model using the first image mapis communicated, e.g., to the content playback device 800. In someembodiments, the network interface 710 of the content delivery system700 performs this operation. In some embodiments, the network interface710 includes a transmitter 711 which performs this operation. Operationproceeds from step 2806 to step 2808.

In step 2808, a second image map to be used to map portions of a frameto segments of the environmental mode is communicated, e.g., to thecontent playback device such as for example content playback device 800.The second image map allocates different size portions of the frame todifferent segments of the environmental model thereby allocatingdifferent numbers of pixels to different segments of said model. Thesecond image map allocates a different number of pixels to a firstsegment of the environmental model than are allocated by the first imagemap. In some embodiments, the network interface 710 of the contentdelivery system performs this operation. In some embodiments, thenetwork interface 710 includes a transmitter 711 which performs thisoperation. Operation proceeds from step 2808 to step 2810.

In step 2810, a second frame including at least a portion of a secondimage to be mapped to the environmental model using the second image mapis communicated e.g., to the content playback device such as for examplecontent playback device 800. The first and second image maps mapdifferent numbers of pixels to an area corresponding to the same portionof an environment thereby providing different resolution allocations forthe same portion of the environment based on which of the first andsecond image maps are used. In some embodiments, the network interface710 of the content delivery system performs this operation. In someembodiments, the network interface 710 includes a transmitter 711 whichperforms this operation. Operation proceeds from step 2810 to step 2804where operation proceeds as previously described.

FIGS. 27, 28 and 29 show how a playback device, such as the playbackdevice or devices shown in any of the other figures, can perform imagerendering using a UV map corresponding to the resolution allocation thatwas used to generate the image to be rendered.

FIG. 27 shows how a reduced resolution image 2404 can be rendered usingthe UV map 2406 and an environmental module 3002 with environmentalsegments in the model corresponding to segments of the UV map. The topportion of FIG. 27 shows the relationship between segments of the UV map2406 and the segments of the environmental model 3002. A first segmentof the UV map 2406 corresponds to a first environmental module segment(EMS 1) of environmental model 3002, as represented by the solid arrowextending from the first segment of the UV map 2406 and EMS 1. A secondenvironmental module segment (EMS 2) of environmental model 3002corresponds to the second segment of the UV map 2406 as indicated by thedashed arrow extending from the second segment of the UV map 2406 andEMS 2. A third environmental module segment (EMS 3) of environmentalmodel 3002 corresponds to the third segment of the UV map 2406 asindicated as represented by the dashed arrow extending from the secondsegment of the UV map 2406 and EMS 3. There is a known, e.g., one toone, relationship between other segments of the UV map 2406 and theenvironmental model 3002.

During rendering, the UV map 2406 is used to determine how to applyportions of an image generated in accordance with the first resolutionallocation to portions of the environmental model 3002, as a texture. Inthe FIG. 27 UV map 2404 is applied to the communicated image 2404 todetermine how to segment the image 2404 into sets of pixels to beapplied to the corresponding segments of the environmental model 3002.The pixels in the segments of the image 2404 corresponding to a segmentof the UV map 2406 are then applied to the corresponding segment of theenvironmental model 3002, e.g., as a texture, with scaling and reshapingbeing used as necessary to cover the surface of the segment of theenvironmental model 3002. The portion of the image applied to thecorresponding segment of the environmental model 3002 is scaled and/oradjusted in shape as necessary to fully occupy the corresponding segmentof the environmental model 3002 in some embodiments. Thus, for example,two pixels of the communicated image corresponding to the first segmentof the UV map 2406 are scaled to fully occupy the first segment EMS1 ofthe environmental model 3002 to which they are applied. Similarly in theFIG. 27 example, the two pixels of the image 2404 being rendered,corresponding to the second segment of the UV map 2406 are scaled tofully occupy the second segment EMS2 of the environmental model 3002 towhich they are applied as a texture. In the FIG. 27 example, the thirdsegment of the UV map corresponds to four pixels of the image 2404 to berendered. The four pixels are applied as a texture to the third segmentEMS3 of the environmental model 3002 as a texture during the renderingprocess. Thus, assuming the third segment of the environmental model3002 is the same size as the first and second segments of theenvironmental model, the third segment will be of higher resolution thanthe first and second segments and correspond to more pixels in thereceived image 2404 than either of the first and second segments. Thusthe segments of the UV map 2406 corresponding to portions of an imagewhich were subject to resolution reduction prior to encoding maycorrespond to the same size area of the environmental model 3002 ofanother segment which does not correspond to a resolution reductionoperation. As should be appreciated the segment corresponding to thearea where resolution reduction was not performed will be displayed inthe generated image of the simulated environment at a higher resolutionthan the portion to which resolution reduction was performed prior toencoding.

As discussed above, different resolution reduction operations may beperformed to produce images that are transmitted. The playback devicewill use a UV map corresponding to the resolution reduction operationthat was performed when rendering the received images. Thus, while theenvironmental model 3002 may remain the same for multiple images,different UV maps 2406, 2506, 2606 may be used with the sameenvironmental model 3002.

FIG. 28 shows the application of UV map 2506 to an image 2504, generatedusing the second selective resolution reduction operation, whichallocates less resolution to the right portion of an image correspondingto a portion of an environment than the left and middle portions. ThusFIG. 28 shows how a reduced resolution image 2504 can be rendered usingthe UV map 2506 and the environmental model 3002 with environmentalsegments corresponding to segments of the UV map. The top portion ofFIG. 28 shows the relationship between segments of the UV map 2506 andthe segments of the environmental model 3002. A first segment of the UVmap 2506 corresponds to the first environmental module segment (EMS 1)of environmental model 3002, as represented by the solid arrow extendingfrom the first segment of the UV map 2506 and EMS 1. A secondenvironmental module segment (EMS 2) of environmental model 3002corresponds to the second segment of the UV map 2506 as indicated by thedashed arrow extending from the second segment of the UV map 2506 andEMS 2. A third environmental module segment (EMS 3) of environmentalmodel 3002 corresponds to the third segment of the UV map 2506 asindicated by the dashed arrow extending from the second segment of theUV map 2506 and EMS 3.

During rendering, the UV map 2506 is used to determine how to apply animage to be rendered to the environmental model 3002. FIG. 28 shows howthe communicated image 2504 and the pixels in the segments of the imagecorresponding to a segment of the UV map are applied to thecorresponding segment of the environmental model 3002. The portion ofthe image 2504 applied to the corresponding segment of the UV map isscaled and/or adjusted in shape as necessary to fully occupy thecorresponding segment of the UV map. Thus, for example, four pixels ofthe communicated image corresponding to the first segment of the UV map2504 are scaled to fully occupy the first segment EMS1 of theenvironmental model to which they are applied. Similarly in the FIG. 28example, the four pixels of the image being rendered, corresponding tothe second segment of the UV map are scaled to fully occupy the secondsegment EMS2 of the environmental model 3002 to which they are appliedas a texture. In the FIG. 28 example, the third segment of the UV mapalso corresponds to four pixels of the image to be rendered. The fourpixels are applied as a texture to the third segment of theenvironmental model as a texture during the rendering process. Thus,assuming the third segment of the environmental model is the same sizeas the first and second segments of the environmental model, the thirdsegment will be of the same resolution as the first and second segments.In accordance with the second resolution allocation scheme resolutionreduction is not applied to the left and middle portions of the imagebut resolution reduction is performed with regard to the right side ofthe image. Thus while the first, second and third segments of therendered image will be of the same resolution in the FIG. 28 example,segments corresponding to the right side of the image and thus the rightside of the environmental model 3002 will be of lower resolution.

FIG. 29 shows the application of UV map 2606 to an image 2604, generatedusing the third selective resolution reduction operation, whichallocates less resolution to the left portion of an image correspondingto a portion of an environment than the middle and right portions. ThusFIG. 28 shows how a reduced resolution image 2604 can be rendered usingthe UV map 2606 and the environmental model 3002 with environmentalsegments corresponding to segments of the UV map 2606. The top portionof FIG. 29 shows the relationship between segments of the UV map 2606and the segments of the environmental model 3002. A first segment of theUV map 2606 corresponds to the first environmental module segment (EMS1) of environmental model 3002, as represented by the solid arrowextending from the first segment of the UV map 2606 and EMS 1. A secondenvironmental model segment (EMS 2) of environmental model 3002corresponds to the second segment of the UV map 2506 as indicated by thedashed arrow extending from the second segment of the UV map 2606 andEMS 2. A third environmental module segment (EMS 3) of environmentalmodel 3002 corresponds to the third segment of the UV map 2606 asindicated by the dashed arrow extending from the second segment of theUV map 2606 and EMS 3.

During rendering, the UV map 2606 is used to determine how to apply animage to be rendered to the environmental model 3002. FIG. 29 shows howthe communicated image 2604 and the pixels in the segments of the imagecorresponding to a segments of the UV map are applied to thecorresponding segments of the environmental model 3002. The portion ofthe image 2604 corresponding to a segment of the environmental model3002 as indicated by the UV map 2606 is scaled and/or adjusted in shapeas necessary to fully occupy the corresponding segment of theenvironmental model 3002. Thus, for example, two pixels of thecommunicated image 2604 corresponding to the first segment of the UV map2606 are scaled to fully occupy the first segment EMS1 of theenvironmental model to which they are applied. Similarly in the FIG. 29example, the two pixels of the image being rendered, corresponding tothe second segment of the UV map 2606 are scaled to fully occupy thesecond segment EMS2 of the environmental model 3002 to which they areapplied as a texture. In the FIG. 29 example, the third segment of theUV map also corresponds to two pixels of the image to be rendered. Thetwo pixels are applied as a texture to the third segment of theenvironmental model 3002 as a texture during the rendering process.Thus, assuming the third segment of the environmental model 3002 is thesame size as the first and second segments of the environmental model3002, the third segment will be of the same resolution as the first andsecond segments. In accordance with the third resolution allocationscheme resolution reduction is not applied to the middle and rightportions of the transmitted image but resolution reduction is performedwith regard to the left side of the image. Thus while the first, secondand third segments of the rendered image will be of the same resolutionin the FIG. 29 example, segments corresponding to the middle and side ofthe image and right side of the environmental model 3002 will be ofhigher resolution.

Thus, by using different UV maps different resolution allocation can beachieved during playback while the size and/or number of pixels in theinput images remains the same. This provides an easy and efficient wayof changing resolution allocations without having to alter the size ornumber of pixels in the images being transmitted.

Another exemplary apparatus for playing back content will now bedescribed. The apparatus includes a receiver for receiving signals, amesh model of an environment, one or more image maps, e.g., UV map(s),indicating a mapping between an image and the mesh model of anenvironment, and one or more encoded images. In some embodiments, thereceiver of the apparatus is configured to receive a mesh model of anenvironment, a first image map, a second image map, and an encodedimage. The apparatus also includes or is coupled to a storage devicesuch as a memory for storing received signals, mesh models, image maps,and images such as encoded, decoded and produced images. The apparatusfurther includes a decoder for decoding received encoded images and aprocessor configured to map a decoded image to a mesh model of anenvironment in accordance with a first image map to produce a firstrendered image. The first image map mapping different numbers of pixelsof the decoded image to different segments of said mesh model of theenvironment. In some embodiments, the apparatus is configured so thatthe different numbers of pixels are mapped to environmental regions ofthe same size but located at different locations in the environment. Insome embodiments, the segments in the environment corresponding toaction are allocated more pixels than segments in which less or noaction is detected. In some embodiments, the apparatus is configured sothat at least some segments corresponding to a front viewing area areallocated more pixels per segment than segments corresponding to a rearviewing area. In some embodiments, the apparatus includes or is coupledto a display device on which images produced by the apparatus aredisplayed. The processor of the apparatus may be, and typically is,configured to operate the apparatus to store received signals, meshmodels, image maps, and images such as encoded, decoded and producedimages in a storage device included in or coupled to the apparatus.

In some embodiments, the receiver of the apparatus is configured toreceive a signal indicating that a second image map should be used tomap portions of received frames to said environmental mesh model. Theprocessor of the apparatus is further configured to operate theapparatus in response to the received signal indicating that a secondimage map should be used to map portions of received frames to theenvironmental mesh model to use a second image map, typically the secondreceived image map, to map portions of received frames to theenvironmental mesh model to produce a second rendered image. In some ofsuch apparatus, the decoded image is a frame and the first image mapallocates a first number of pixels of the frame to a first segment ofthe environmental mesh model and the second image map allocates a secondnumber of pixels of the frame to the first segment of the environmentalmesh model, the first and second number of pixels being different. Theprocessor the apparatus is typically configured to display the secondrendered image to a display which may be either included as part of theapparatus or coupled to the apparatus.

An exemplary apparatus for communicating information to be used torepresent an environment will now be discussed. The exemplary apparatusincludes a processor configured to operate said apparatus to: (i)communicate a first image map to be used to map portions of a frame tosegments of an environmental model, the first image map allocatingdifferent size portions of the frame to different segments of theenvironmental model thereby allocating different numbers of pixels todifferent segments of the model, and (ii) communicate a first frameincluding at least a portion of a first image to be mapped to saidenvironmental model using said first image map.

In some embodiments, the processor of the apparatus is furtherconfigured to operate the apparatus to: (i) communicate a second imagemap to be used to map portions of a frame to segments of theenvironmental model, said second image map allocating different sizeportions of the frame to different segments of the environmental modelthereby allocating different numbers of pixels to different segments ofsaid model, the second image map allocating a different number of pixelsto a first segment of said model than are allocated by said first imagemap, e.g., UV map, and (ii) communicate a second frame including atleast a portion of a second image to be mapped to said environmentalmodel using the second image map. In some embodiments of the apparatus,the first and second image maps map different numbers of pixels to anarea corresponding to the same portion of an environment therebyproviding different resolution allocations for said same portion of theenvironment based on which of the first and second image maps are used.

In some embodiments, the apparatus is a server providing a real timecontent stream. In some embodiments, the apparatus is a real timecontent delivery system including an environmental mesh generationmodule, a map generation module, e.g., UV map generation module, and anI/O interface and/or an network interface for communicating informationincluding signals, models, maps and images. In some embodiments, themodules include software instructions which when executed cause theprocessor to perform various routines. In some embodiments, the modulesare hardware modules, e.g., circuitry. In some embodiments, the modulesare a combination of hardware and software modules.

An exemplary content processing and delivery system, e.g., system 700,implemented in accordance with one exemplary embodiment comprises: aprocessor (e.g., processor 708) configured to: i) select a firstresolution allocation to be used for at least one image corresponding toa first portion of an environment; and ii) perform a resolutionreduction operation on a first image of the first portion of theenvironment in accordance with the selected first resolution allocationto generate a first reduced resolution image; and a transmitter (e.g., atransmitter 713 of interface 710) configured to communicate the firstreduced resolution image to a playback device.

In some embodiments selection of a resolution allocation is performedbased on a region of importance in the first portion of the environment.In some embodiments the region of importance corresponds to an area ofmotion in the first portion of the environment. In some embodiments theregion of importance is a region indicated by a system operator. In someembodiments the region of importance is a region determined by detectingwhich portion of the environment included in the first image one or moreindividuals is looking at prior to or at the time the first image iscaptured.

In some embodiments the transmitter is further configured to:communicate to the playback device a first texture map (UV map) to beused to map portions of the images generated in accordance with thefirst resolution allocation to a surface of a model of the environment.In some embodiments the size of a first segment in the first texture mapis a function of the amount of resolution reduction applied to acorresponding first area of the first image to generate a first segmentof the first reduced resolution image. In some embodiments the firsttexture map includes a second segment corresponding to a portion of thefirst image which was not subject to a resolution reduction operation,the size of the second segment in the second texture map being the sameas the size of the segment in the first image.

In some embodiments the size of the first segment in the texture map isreduced from the size of the source of the corresponding area in thefirst image by an amount which is based on the amount of resolutionreduction applied to the corresponding first area of the first image. Insome embodiments the transmitter is further configured to communicate tothe playback device an environmental model. In some embodiments thefirst texture map corresponds to a portion of the environmental model,the first texture map providing information indicating how to mapportions of images subject to the first resolution allocation to aportion of the environmental model. In some embodiments the first imageis one image of an image pair the first image and a second image, thefirst image being one of a left and right eye image pair, the secondimage being a second one of a left and right eye image pair. In someembodiments the processor is further configured to perform a resolutionreduction operation on the second image in accordance with the selectedfirst resolution allocation to generate a second reduced resolutionimage, and the transmitter is further configured to communicate thesecond reduced resolution image to the playback device as part of afirst stereoscopic image pair.

In some embodiments the processor is further configured to: select asecond resolution allocation to be used for another image correspondingto a first portion of the environment, the another image being a thirdimage; and perform a resolution reduction operation on the third imagein accordance with the selected second resolution allocation to generatea third reduced resolution image. In some embodiments the transmitter isfurther configured to communicate the third reduced resolution image toa playback device.

In some embodiments the transmitter is further configured to communicateto the playback device a second texture map (UV map) to be used to mapportions of images generated in accordance with the second resolutionallocation to the surface of the model of the environment. In someembodiments the size of a first segment in the second texture map is afunction of the amount of resolution reduction applied to acorresponding first area of the third image to generate a first segmentof the third reduced resolution image. In some embodiments the secondtexture map includes a third segment corresponding to a portion of thethird image which was not subject to a resolution reduction operation,the size of the third segment in the second texture map being the sameas the size of the segment in the third image.

In some embodiments the size of the first segment in the second texturemap is reduced from the size of the source of the corresponding area inthe third image by an amount which is based on the amount of resolutionreduction applied to the corresponding first area of the third image. Insome embodiments the second texture map corresponds to the same portionof the environmental model as the first texture map, the second texturemap providing information indicating how to map portions of imagessubject to the second resolution allocation to a corresponding portionof the environmental model.

The methods and apparatus can be used for rendering stereoscopic images,e.g., pairs of images to be displayed to a users left and right eyes, ormono-scopic images. Thus while the methods are well suited for use insimulating 3D environments they are also well suited for use incommunicating panoramic images which may correspond to an area less thana full 360 degree environment and which may not be stereoscopic innature.

Numerous additional methods and embodiments are described in thedetailed description which follows.

While steps are shown in an exemplary order it should be appreciatedthat in many cases the order of the steps may be altered withoutadversely affecting operation. Accordingly, unless the exemplary orderof steps is required for proper operation, the order of steps is to beconsidered exemplary and not limiting.

Some embodiments are directed a non-transitory computer readable mediumembodying a set of software instructions, e.g., computer executableinstructions, for controlling a computer or other device to encode andcompresses stereoscopic video. Other embodiments are embodiments aredirected a computer readable medium embodying a set of softwareinstructions, e.g., computer executable instructions, for controlling acomputer or other device to decode and decompresses video on the playerend. While encoding and compression are mentioned as possible separateoperations, it should be appreciated that encoding may be used toperform compression and thus encoding may, in some include compression.Similarly, decoding may involve decompression.

The techniques of various embodiments may be implemented using software,hardware and/or a combination of software and hardware. Variousembodiments are directed to apparatus, e.g., a image data processingsystem. Various embodiments are also directed to methods, e.g., a methodof processing image data. In some embodiments, one or more of the methodsteps is implemented using a processor. Various embodiments are alsodirected to a non-transitory machine, e.g., computer, readable medium,e.g., ROM, RAM, CDs, hard discs, etc., which include machine readableinstructions for controlling a machine to implement one or more steps ofa method.

Various features of the present invention are implemented using modules.Such modules may, and in some embodiments are, implemented as softwaremodules. In other embodiments the modules are implemented in hardware.In still other embodiments the modules are implemented using acombination of software and hardware. In some embodiments the modulesare implemented as individual circuits with each module beingimplemented as a circuit for performing the function to which the modulecorresponds. A wide variety of embodiments are contemplated includingsome embodiments where different modules are implemented differently,e.g., some in hardware, some in software, and some using a combinationof hardware and software. It should also be noted that routines and/orsubroutines, or some of the steps performed by such routines, may beimplemented in dedicated hardware as opposed to software executed on ageneral purpose processor. Such embodiments remain within the scope ofthe present invention. Many of the above described methods or methodsteps can be implemented using machine executable instructions, such assoftware, included in a machine readable medium such as a memory device,e.g., RAM, floppy disk, etc. to control a machine, e.g., general purposecomputer with or without additional hardware, to implement all orportions of the above described methods. Accordingly, among otherthings, the present invention is directed to a machine-readable mediumincluding machine executable instructions for causing a machine, e.g.,processor and associated hardware, to perform one or more of the stepsof the above-described method(s).

Numerous additional variations on the methods and apparatus of thevarious embodiments described above will be apparent to those skilled inthe art in view of the above description. Such variations are to beconsidered within the scope.

What is claimed:
 1. A method of operating a content playback device, themethod comprising: storing a plurality of texture maps corresponding todifferent resolution allocations, different resolution allocationscorresponding to different patterns of non-uniform image downsampling;receiving a first encoded image, said first encoded image representing afirst image in encoded form, said first image including at least a firstimage portion that was downsampled in accordance with a first resolutionallocation and a second image portion which, in accordance with saidfirst resolution allocation, was left at full resolution or subject to alesser amount of resolution reduction than said first image portion;receiving information indicating which of said plurality of texture mapsis to be used with the first image, said information identifying a firsttexture map corresponding to said first resolution allocation, differenttexture maps in said plurality of texture maps corresponding todifferent resolution allocations; decoding the first encoded image torecover said first image; using the first texture map corresponding tothe first resolution allocation to apply at least the first imageportion of said first image to a surface of a first portion of a modelof an environment to generate a first rendered image; and outputting thefirst rendered image to a display device.
 2. The method of claim 1,further comprising: receiving a second encoded image, said secondencoded image representing a second image in encoded form, said secondimage including at least a third image portion that was downsampled inaccordance with a second resolution allocation and an additional imageportion which, in accordance with said second resolution allocation, wasleft at full resolution or subject to a lesser amount of resolutionreduction than said third image portion; decoding the second encodedimage to recover the second image; and using a second texture mapcorresponding to a second resolution allocation to apply at least thethird image portion of said third image to the surface of the firstportion of the model of the environment to generate an additionalrendered image; and outputting the additional rendered image to thedisplay.
 3. The method of claim 2, wherein storing a plurality oftexture maps includes: storing said first texture map and said secondtexture map in memory in said content playback device prior to receivingsaid first and second encoded images.
 4. The method of claim 2, furthercomprising: receiving, prior to using the second texture map, a secondindicator indicating that the second texture map in said plurality oftexture maps is to be used with the second image.
 5. The method of claim2, wherein said different patterns of non-uniform image downsamplingcorrespond to patterns which when used for downsampling controldownsampling on different portions of an image by different amounts,said first portion of said first image having been downsampled by afirst amount, said third image portion of the second image or saidadditional image portion of said second image having been downsampled inaccordance with said second resolution allocation by a different amountthan said first amount.
 6. The method of claim 2, wherein said differentpatterns of non-uniform image downsampling correspond to patterns whichwhen used for downsampling control downsampling on different portions ofan image by different amounts, said first portion of said first imagehaving been downsampled by a first amount, said third image portion ofthe second image having been downsampled in accordance with said secondresolution allocation by a different amount than said first amount. 7.The method of claim 1, wherein said information indicating which of saidplurality of texture maps is to be used with the first image is a firstindicator identifying the first texture map.
 8. The method of claim 1,wherein said different patterns of non-uniform image downsamplingcorrespond to patterns which when used for downsampling controldownsampling on different portions of an image by different amounts. 9.A content playback device comprising: a memory storing a plurality oftexture maps corresponding to different resolution allocations,different resolution allocations corresponding to different patterns ofnon-uniform image downsampling; a receiver; a decoder; a processor, saidprocessor configured to control said content playback device to: i)receive a first encoded image, said first encoded image representing afirst image in encoded form, said first image including at least a firstimage portion that was downsampled in accordance with a first resolutionallocation and a second image portion which, in accordance with saidfirst resolution allocation, was left at full resolution or subject to alesser amount of resolution reduction than said first image portion; ii)receive information indicating which of said plurality of texture mapsis to be used with the first image, said information identifying a firsttexture map corresponding to said first resolution allocation, differenttexture maps in said plurality of texture maps corresponding todifferent resolution allocations; iii) decode the first encoded image torecover said first image; and iv) use the first texture mapcorresponding to the first resolution allocation to apply at least thefirst image portion of said first image to a surface of a first portionof a model of an environment to generate a first rendered image; and adisplay for displaying images rendered by the processor.
 10. The contentplayback device of claim 9, wherein said processor is further configuredto control said content playback device to store said first texture mapand said second texture map in said memory.
 11. The content playbackdevice of claim 10, wherein said information indicating which of saidplurality of texture maps is to be used with the first image is a firstindicator identifying the first texture map.
 12. The content playbackdevice of claim 11, wherein the processor is further configured tocontrol the content playback device to: receive a second encoded image,said second encoded image representing a second image in encoded form,said second image including at least a third image portion that wasdownsampled in accordance with a second resolution allocation and anadditional image portion which, in accordance with said secondresolution allocation, was left at full resolution or subject to alesser amount of resolution reduction than said third image portion;decode the second encoded image to recover the second image; and use asecond texture map corresponding to the second resolution allocation toapply at least the third image portion of said second image to thesurface of the first portion of the model of the environment to generatean additional rendered image.
 13. The content playback device of claim12, wherein said processor is further configured to control said contentplayback device to receive a second indicator indicating which of theplurality of texture maps corresponding to different resolutionallocations is to be used with the second image, said second indicatoridentifying the second texture map.
 14. A non-transitory computerreadable medium comprising processor executable instructions, which whenexecuted by a processor, control a content playback device to: store aplurality of texture maps corresponding to different resolutionallocations, different resolution allocations corresponding to differentpatterns of non-uniform image downsampling; receive a first encodedimage, said first encoded image representing a first image in encodedform, said first image including at least a first image portion that wasdownsampled in accordance with a first resolution allocation and asecond image portion which, in accordance with said first resolutionallocation, was left at full resolution or subject to a lesser amount ofresolution reduction than said first image portion; receive informationindicating which of said plurality of texture maps is to be used withthe first image, said information identifying a first texture mapcorresponding to said first resolution allocation, different texturemaps in said plurality of texture maps corresponding to differentresolution allocations; decode the first encoded image to recover saidfirst image; use the first texture map corresponding to the firstresolution allocation to apply at least the first image portion of saidfirst image to a surface of a first portion of a model of an environmentto generate a first rendered image; and display the first rendered imageon a display.